feat: author ${VAR} references, gated on whether the client expands them (#76)

The blocker on this issue was whether BCC or the client does the expanding.
Answer, from Anthropic's docs: Claude Code expands ${VAR} and
${VAR:-default} itself, in command, args, env, url and headers, for both
project .mcp.json and user-scope ~/.claude.json. Claude Desktop has no
documented support.

So this is a per-client capability, not a global one, and BCC does NOT
expand on write: resolving a reference into the file would put the secret
back on disk -- the whole thing the user is avoiding -- and would defeat a
feature the client already implements correctly. BCC authors, validates and
warns; expand_env_refs exists to preview what the client will do.

Semantics mirror the documented ones exactly, including the unusual bit:
an unset variable with no default is left as literal ${VAR} text rather
than blanked, because that is what Claude Code passes through.

Gating uses the existing profile_targets_claude_desktop(), so a config that
is correct under Claude Code and broken under Desktop is reported against
whichever profile is actually loaded. The two warnings are worded
differently on purpose -- 'this client will never expand these' is a
different problem from 'this variable looks unset here'.

Two existing behaviours were backwards for this feature and are fixed:

- Secret masking hid placeholders. is_secret_key('API_KEY') is true, so
  ${API_KEY} rendered as dots -- making a reference indistinguishable from
  a stored credential, which is the one distinction that makes the feature
  worth adopting. should_mask_value() now skips references, in the table
  delegate, _redact_server_data and redact_args alike.
- args_secret_warning fired on placeholders. Moving a token into ${VAR} is
  the recommended fix for that warning; continuing to warn punished the
  fix. It now skips references while still flagging a real secret that
  follows one.

Real secrets are still masked everywhere they were before -- asserted, not
assumed.

Refs #76

.github/workflows/ci.yml

@@ -120,7 +120,7 @@ jobs:
       # below to the new key's base64 form, as its own reviewed change.
       - name: Verify data/catalog.json.sig
         env:
-          EXPECTED_CATALOG_PUBKEY_B64: "0s24PmkZcTT5yxNDdyTPHl5fyxArrHNPJKBjnXoQd8k="
+          EXPECTED_CATALOG_PUBKEY_B64: "082NOwVB7uURkvfyS3+knJ+40Fk6C9unsF47+2uPKo4="
         run: |
           python - <<'PY'
           import base64, os, pathlib, sys

README.md

@@ -90,21 +90,6 @@ key, because they protect different things and live in different places:
 | Generated with | `python catalog_console.py keygen` | `python catalog_console.py keygen --release` |
 | Exported for CI with | *(never — there is no supported way to export this key)* | `python catalog_console.py show-seed-b64 --release` |
 
-**Confused about which key is which, or what state either is in?** Run:
-
-```bash
-python catalog_console.py keys
-```
-
-It needs no passphrase (it never touches private key bytes) and prints a
-plain-English report for both keys: where each private half lives, whether
-it's present on this machine, its fingerprint, whether that fingerprint
-matches what's actually committed in `bcc_core.py`, `ci.yml`'s trust
-anchor, and `scripts/sign_checksums.py`, and whether
-`data/catalog.json.sig` currently verifies — ending with the exact command
-to run next for whatever state it finds. This is the check that would have
-caught [issue #68](../../issues/68)'s finding 5 incident before it happened.
-
 **Why two keys:** the catalog key is the root of trust for what BCC
 actually *executes* on a user's machine — every `command`/`args` pair in
 the shipped catalog is only there because this key signed it. If that key
@@ -125,29 +110,12 @@ refuses to run without `--release` specifically so the catalog seed can't
 be exported by habit or muscle memory.
 
 **Release signing public key** (Ed25519, base64, raw 32 bytes) — this is
-the RELEASE key, which signs `SHA256SUMS` (release checksums). It does
+the RELEASE key, not the catalog key:
-**not** sign `data/catalog.json` and is not the key `bcc_core.CATALOG_PUBKEYS`
-trusts:
 
 ```
-6BnPgJEHJFyVltFoLTCNadIsehjy00iiW8IRlC1TfhA=
+<PLACEHOLDER — AJ: paste the release public key from `catalog_console.py keygen --release` here>
 ```
 
-The catalog public key (Ed25519, base64, raw 32 bytes) — this is the key
-that signs `data/catalog.json` and is trusted via `bcc_core.CATALOG_PUBKEYS`
-and the CI trust anchor in `.github/workflows/ci.yml`. It is listed here
-for completeness, not because you need it to verify a download — use the
-*release* key above for that:
-
-```
-0s24PmkZcTT5yxNDdyTPHl5fyxArrHNPJKBjnXoQd8k=
-```
-
-Both keys above were rotated 2026-07 — see [issue #68](../../issues/68)
-finding 5. The prior (shared) key is retired and is deliberately **not**
-kept in either trust list; retaining a burned key would defeat the point
-of rotating it.
-
 ## Run from source
 
 ```bash
@@ -222,7 +190,7 @@ file is also listed, marked *legacy*, so you can copy them over.
 - `bcc.spec` — PyInstaller build spec (cross-platform).
 - `scripts/build_icons.py` — regenerates `icons/app.icns` and `icons/app.ico` from source PNGs.
 - `scripts/sign_checksums.py` — generates and Ed25519-signs the release `SHA256SUMS` manifest (see [Verifying your download](#verifying-your-download)).
-- `catalog_console.py` / `catalog_review.py` — **maintainer-only**, never shipped to users (excluded from `bcc.spec`; see `tests/test_catalog_console_packaging.py`). The Catalog Console: review + sign `data/catalog.json` (against `main`, an open PR, or the branch you have checked out — `--ref <branch>` to be explicit, e.g. mid key-rotation, so a rotation can be signed and pushed to its own branch *before* it's merged, never forcing a red `main`), generate/manage both signing keys (`keygen`, `keygen --release`), and report on their status (`keys`, no passphrase needed) — see [Signing keys](#signing-keys).
+- `catalog_console.py` / `catalog_review.py` — **maintainer-only**, never shipped to users (excluded from `bcc.spec`; see `tests/test_catalog_console_packaging.py`). The Catalog Console: review + sign `data/catalog.json`, and generate/manage both signing keys (`keygen`, `keygen --release`) — see [Signing keys](#signing-keys).
 
 ## Building from source
 

bcc.py

@@ -10,6 +10,7 @@ Run:  python mcp_manager.py
 
 from __future__ import annotations
 
+import contextlib
 import sys
 import time
 from pathlib import Path
@@ -18,6 +19,7 @@ from typing import ClassVar
 from PySide6.QtCore import QRect, QSettings, QSize, Qt, QThread, QTimer, QUrl, Signal
 from PySide6.QtGui import (
     QAction,
+    QActionGroup,
     QColor,
     QCursor,
     QDesktopServices,
@@ -25,6 +27,7 @@ from PySide6.QtGui import (
     QIcon,
     QKeySequence,
     QPainter,
+    QPalette,
     QPixmap,
 )
 from PySide6.QtWidgets import (
@@ -65,85 +68,122 @@ import bcc_core as core
 # thread during drag-and-drop import, so skip anything larger than this.
 MAX_DROP_IMPORT_BYTES = 5 * 1024 * 1024  # 5 MB
 
-# --- One-line rebrand: change this to recolor the whole app --------------- #
+# --- Theming (issue #75) -------------------------------------------------- #
-ACCENT = "#f97316"  # warm orange
+# The palette lives in bcc_core (testable without a Qt app); these module-level
-ACCENT_DIM = "#c2570b"
+# names are rebound by `apply_palette()` whenever the theme changes.
-BG = "#1b1d23"
+#
-PANEL = "#23262e"
+# Why globals rather than passing a palette around: ~20 inline
-PANEL_2 = "#2b2f39"
+# `setStyleSheet(f"color: {MUTED}")` calls are scattered through this file, and
-TEXT = "#e7e9ee"
+# an f-string resolves its names when it runs, not when it's compiled. Rebinding
-MUTED = "#9aa0ad"
+# the globals means every one of those call sites picks up the new colour on its
-BORDER = "#3a3f4b"
+# next render, with no change to the call sites themselves.
-GOOD = "#4ade80"
+PALETTE = core.DARK_PALETTE
-BAD = "#f87171"
+ACCENT = ACCENT_DIM = BG = PANEL = PANEL_2 = TEXT = MUTED = BORDER = ""
-WARN = "#fbbf24"
+GOOD = BAD = WARN = REMOTE = ON_ACCENT = DISABLED_BG = MONO_BG = SEL_TEXT = ""
+STATUS_COLORS: dict[str, str] = {}
+HEALTH_COLORS: dict[str, str] = {}
 
-STATUS_COLORS = {"ok": GOOD, "missing": BAD, "warn": WARN, "remote": "#60a5fa", "unknown": WARN}
+STATUS_GLYPH = {
-STATUS_GLYPH = {"ok": "●", "missing": "●", "warn": "▲", "remote": "◆", "unknown": "○"}
+    "ok": "\u25cf",
+    "missing": "\u25cf",
+    "warn": "\u25b2",
+    "remote": "\u25c6",
+    "unknown": "\u25cb",
+}
 
 # Health dot (spawn-test outcome, see core.HealthStatus) shown per row in the
 # server tables' "Health" column -- distinct from the PATH-dependency Status
 # column above.
-HEALTH_COLORS = {"ok": GOOD, "failed": BAD, "untested": MUTED}
+HEALTH_GLYPH = {"ok": "\u25cf", "failed": "\u25cf", "untested": "\u25cb"}
-HEALTH_GLYPH = {"ok": "●", "failed": "●", "untested": "○"}
 
-STYLESHEET = f"""
+
+def build_stylesheet(p: core.Palette) -> str:
+    """Render the global QSS for a palette."""
+    return f"""
 /* No font-family here on purpose: Qt already uses the native system UI font
    on every platform (San Francisco / Segoe UI / desktop default). Naming
    web-CSS aliases like -apple-system forces a costly font-alias scan. */
-* {{ font-size: 13px; color: {TEXT}; }}
+* {{ font-size: 13px; color: {p.text}; }}
-QMainWindow, QDialog {{ background: {BG}; }}
+QMainWindow, QDialog {{ background: {p.bg}; }}
 QLabel#h1 {{ font-size: 15px; font-weight: 600; }}
-QLabel#muted {{ color: {MUTED}; }}
+QLabel#muted {{ color: {p.muted}; }}
-QFrame#card {{ background: {PANEL}; border: 1px solid {BORDER}; border-radius: 10px; }}
+QFrame#card {{ background: {p.panel}; border: 1px solid {p.border}; border-radius: 10px; }}
 QLineEdit, QPlainTextEdit, QComboBox {{
-    background: {PANEL_2}; border: 1px solid {BORDER}; border-radius: 7px;
+    background: {p.panel_2}; border: 1px solid {p.border}; border-radius: 7px;
-    padding: 6px 8px; selection-background-color: {ACCENT}; selection-color: #1a1205;
+    padding: 6px 8px; selection-background-color: {p.accent}; selection-color: {p.on_accent};
 }}
-QLineEdit:focus, QPlainTextEdit:focus, QComboBox:focus {{ border: 1px solid {ACCENT}; }}
+QLineEdit:focus, QPlainTextEdit:focus, QComboBox:focus {{ border: 1px solid {p.accent}; }}
 QComboBox::drop-down {{ border: none; width: 22px; }}
-QComboBox QAbstractItemView {{ background: {PANEL_2}; border: 1px solid {BORDER};
+QComboBox QAbstractItemView {{ background: {p.panel_2}; border: 1px solid {p.border};
-    selection-background-color: {ACCENT}; outline: none; }}
+    selection-background-color: {p.accent}; outline: none; }}
-QPushButton {{ background: {PANEL_2}; border: 1px solid {BORDER}; border-radius: 7px;
+QPushButton {{ background: {p.panel_2}; border: 1px solid {p.border}; border-radius: 7px;
     padding: 7px 13px; }}
-QPushButton:hover {{ border: 1px solid {ACCENT}; }}
+QPushButton:hover {{ border: 1px solid {p.accent}; }}
-QPushButton:disabled {{ color: {MUTED}; background: {PANEL}; }}
+QPushButton:disabled {{ color: {p.muted}; background: {p.panel}; }}
-QPushButton#primary {{ background: {ACCENT}; border: 1px solid {ACCENT}; color: #1a1205; font-weight: 600; }}
+QPushButton#primary {{ background: {p.accent}; border: 1px solid {p.accent}; color: {p.on_accent}; font-weight: 600; }}
-QPushButton#primary:hover {{ background: {ACCENT_DIM}; }}
+QPushButton#primary:hover {{ background: {p.accent_dim}; }}
-QPushButton#primary:disabled {{ background: {PANEL}; color: {MUTED}; border: 1px solid {BORDER}; }}
+QPushButton#primary:disabled {{ background: {p.panel}; color: {p.muted}; border: 1px solid {p.border}; }}
-QPushButton#danger:hover {{ border: 1px solid {BAD}; color: {BAD}; }}
+QPushButton#danger:hover {{ border: 1px solid {p.bad}; color: {p.bad}; }}
-QTableWidget {{ background: {PANEL}; border: 1px solid {BORDER}; border-radius: 10px;
+QTableWidget {{ background: {p.panel}; border: 1px solid {p.border}; border-radius: 10px;
     gridline-color: transparent; outline: none; }}
 QTableWidget::item {{ padding: 6px 8px; border: none; }}
-QTableWidget::item:selected {{ background: {ACCENT}; color: #1a1205; }}
+QTableWidget::item:selected {{ background: {p.accent}; color: {p.on_accent}; }}
 /* Inline cell editors: the global QLineEdit padding/radius clips the text
    inside a table row, so give editors a compact, flat style instead. */
 QTableWidget QLineEdit {{
-    background: {PANEL_2}; color: {TEXT}; border: 1px solid {ACCENT};
+    background: {p.panel_2}; color: {p.text}; border: 1px solid {p.accent};
     border-radius: 3px; padding: 0px 4px; margin: 0px;
-    selection-background-color: {ACCENT_DIM}; selection-color: #ffffff;
+    selection-background-color: {p.accent_dim}; selection-color: {p.selection_text};
 }}
-QHeaderView::section {{ background: {PANEL}; color: {MUTED}; border: none;
+QHeaderView::section {{ background: {p.panel}; color: {p.muted}; border: none;
-    border-bottom: 1px solid {BORDER}; padding: 8px; font-weight: 600; }}
+    border-bottom: 1px solid {p.border}; padding: 8px; font-weight: 600; }}
 QScrollBar:vertical {{ background: transparent; width: 10px; margin: 2px; }}
-QScrollBar::handle:vertical {{ background: {BORDER}; border-radius: 5px; min-height: 24px; }}
+QScrollBar::handle:vertical {{ background: {p.border}; border-radius: 5px; min-height: 24px; }}
 QScrollBar::add-line, QScrollBar::sub-line {{ height: 0; }}
-QLabel#statusbar {{ color: {MUTED}; padding: 4px 2px; }}
+QLabel#statusbar {{ color: {p.muted}; padding: 4px 2px; }}
-QLabel#warnBanner {{ color: #1a1205; background: {WARN}; border-radius: 8px; padding: 8px 10px; font-weight: 600; }}
+QLabel#warnBanner {{ color: {p.on_accent}; background: {p.warn}; border-radius: 8px; padding: 8px 10px; font-weight: 600; }}
-QLabel#section {{ color: {MUTED}; font-weight: 600; font-size: 12px; padding: 2px 2px; }}
+QFrame#noticeBanner {{ background: {p.panel_2}; border: 1px solid {p.accent}; border-radius: 8px; }}
-QLabel#sectionDisabled {{ color: {MUTED}; font-weight: 600; font-size: 12px; padding: 2px 2px; }}
+QLabel#noticeText {{ color: {p.text}; }}
-QLabel#placeholder {{ color: {MUTED}; padding: 12px; background: {PANEL_2}; border: 1px dashed {BORDER}; border-radius: 8px; }}
+QPushButton#noticeClose {{ background: transparent; border: none; color: {p.muted}; font-size: 14px; padding: 2px; }}
-QTableWidget#disabledTable {{ background: #202229; }}
+QPushButton#noticeClose:hover {{ color: {p.text}; }}
-QTableWidget#disabledTable::item:selected {{ background: {ACCENT}; color: #1a1205; }}
+QLabel#section {{ color: {p.muted}; font-weight: 600; font-size: 12px; padding: 2px 2px; }}
+QLabel#sectionDisabled {{ color: {p.muted}; font-weight: 600; font-size: 12px; padding: 2px 2px; }}
+QLabel#placeholder {{ color: {p.muted}; padding: 12px; background: {p.panel_2}; border: 1px dashed {p.border}; border-radius: 8px; }}
+QTableWidget#disabledTable {{ background: {p.disabled_bg}; }}
+QTableWidget#disabledTable::item:selected {{ background: {p.accent}; color: {p.on_accent}; }}
 QPlainTextEdit#diag {{ font-family: "Menlo", "Cascadia Code", "Consolas", "DejaVu Sans Mono", monospace;
-    font-size: 12px; background: #16181d; border: 1px solid {BORDER}; border-radius: 8px; }}
+    font-size: 12px; background: {p.mono_bg}; border: 1px solid {p.border}; border-radius: 8px; }}
 QFrame#diagCard {{ background: transparent; border: none; }}
 QSplitter::handle {{ background: transparent; }}
-QSplitter::handle:hover {{ background: {BORDER}; border-radius: 4px; }}
+QSplitter::handle:hover {{ background: {p.border}; border-radius: 4px; }}
-QSplitter::handle:pressed {{ background: {ACCENT}; border-radius: 4px; }}
+QSplitter::handle:pressed {{ background: {p.accent}; border-radius: 4px; }}
 """
 
 
+def apply_palette(p: core.Palette) -> str:
+    """Rebind the module-level colour names to `p` and return its stylesheet."""
+    global PALETTE, ACCENT, ACCENT_DIM, BG, PANEL, PANEL_2, TEXT, MUTED, BORDER
+    global GOOD, BAD, WARN, REMOTE, ON_ACCENT, DISABLED_BG, MONO_BG, SEL_TEXT
+    global STATUS_COLORS, HEALTH_COLORS
+    PALETTE = p
+    ACCENT, ACCENT_DIM = p.accent, p.accent_dim
+    BG, PANEL, PANEL_2 = p.bg, p.panel, p.panel_2
+    TEXT, MUTED, BORDER = p.text, p.muted, p.border
+    GOOD, BAD, WARN, REMOTE = p.good, p.bad, p.warn, p.remote
+    ON_ACCENT, DISABLED_BG, MONO_BG, SEL_TEXT = (
+        p.on_accent,
+        p.disabled_bg,
+        p.mono_bg,
+        p.selection_text,
+    )
+    STATUS_COLORS = {"ok": GOOD, "missing": BAD, "warn": WARN, "remote": REMOTE, "unknown": WARN}
+    HEALTH_COLORS = {"ok": GOOD, "failed": BAD, "untested": MUTED}
+    return build_stylesheet(p)
+
+
+STYLESHEET = apply_palette(core.DARK_PALETTE)
+
+
 # --------------------------------------------------------------------------- #
 # Background reachability tester (keeps the UI responsive during the request)
 # --------------------------------------------------------------------------- #
@@ -228,7 +268,7 @@ class _SecretMaskDelegate(QStyledItemDelegate):
         if self.revealed or not option.text:
             return
         key_item = self._table.item(index.row(), 0)
-        if key_item and core.is_secret_key(key_item.text()):
+        if key_item and core.should_mask_value(key_item.text(), option.text):
             option.text = core.MASK
 
 
@@ -1493,6 +1533,54 @@ class AboutDialog(QDialog):
         QDesktopServices.openUrl(QUrl(self._release_url or core.RELEASES_URL))
 
 
+class NoticeBanner(QFrame):
+    """A persistent, dismissible notice with an optional action button.
+
+    The status bar is the wrong home for anything the user needs to act on --
+    21 call sites rewrite it, so a message posted there is gone by the next
+    click. That wiped the MSIX warning (#35) and then the update notice (#78).
+    This is the shared mechanism so it doesn't happen a third time.
+    """
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setObjectName("noticeBanner")
+        row = QHBoxLayout(self)
+        row.setContentsMargins(10, 8, 8, 8)
+        row.setSpacing(8)
+        self._label = QLabel("")
+        self._label.setObjectName("noticeText")
+        self._label.setWordWrap(True)
+        row.addWidget(self._label, 1)
+        self._action_btn = QPushButton("")
+        self._action_btn.setCursor(Qt.CursorShape.PointingHandCursor)
+        self._action_btn.hide()
+        row.addWidget(self._action_btn)
+        self._close_btn = QPushButton("\u2715")
+        self._close_btn.setObjectName("noticeClose")
+        self._close_btn.setCursor(Qt.CursorShape.PointingHandCursor)
+        self._close_btn.setFixedWidth(26)
+        self._close_btn.setToolTip("Dismiss")
+        self._close_btn.clicked.connect(self.hide)
+        row.addWidget(self._close_btn)
+        self.hide()
+
+    def show_notice(self, text: str, action_label: str = "", on_action=None):
+        self._label.setText(text)
+        self._label.setToolTip(text)
+        # Reconnect cleanly: a banner reused for a second notice would
+        # otherwise fire the previous notice's action too.
+        with contextlib.suppress(RuntimeError, TypeError):
+            self._action_btn.clicked.disconnect()
+        if action_label and on_action is not None:
+            self._action_btn.setText(action_label)
+            self._action_btn.clicked.connect(lambda _=False: on_action())
+            self._action_btn.show()
+        else:
+            self._action_btn.hide()
+        self.show()
+
+
 # --------------------------------------------------------------------------- #
 # Restart worker: core.restart_claude_desktop() blocks up to ~5 s on macOS
 # waiting for the old instance to exit, so it must run off the UI thread.
@@ -1550,6 +1638,11 @@ class MainWindow(QMainWindow):
         self.warn_banner.hide()
         root.addWidget(self.warn_banner)
 
+        # Update availability gets its own persistent banner rather than a
+        # status-line write, which the next UI action overwrites (#78).
+        self.update_banner = NoticeBanner(self)
+        root.addWidget(self.update_banner)
+
         # User-draggable divider between the server list and the editor.
         split = QSplitter(Qt.Orientation.Horizontal)
         split.setChildrenCollapsible(False)
@@ -1585,11 +1678,96 @@ class MainWindow(QMainWindow):
 
     # --- menu bar ---------------------------------------------------------- #
     def _build_menu_bar(self):
+        view_menu = self.menuBar().addMenu("&View")
+        theme_menu = view_menu.addMenu("Theme")
+        self._theme_group = QActionGroup(self)
+        self._theme_group.setExclusive(True)
+        current = stored_theme_setting()
+        for setting, label in (
+            (core.THEME_SYSTEM, "Match system"),
+            (core.THEME_LIGHT, "Light"),
+            (core.THEME_DARK, "Dark"),
+        ):
+            act = QAction(label, self, checkable=True)
+            act.setChecked(setting == current)
+            act.triggered.connect(lambda _checked=False, s=setting: self._set_theme(s))
+            self._theme_group.addAction(act)
+            theme_menu.addAction(act)
+
         help_menu = self.menuBar().addMenu("&Help")
+
+        # "Check for updates" used to exist only as a button inside the About
+        # dialog, which is not somewhere anyone looks for it (#79).
+        update_action = QAction("Check for updates…", self)
+        # Explicit role: macOS relocates actions it recognises by text, and
+        # some Qt versions treat "update" as application-menu material. Pin it
+        # so the item stays where the menu says it is on every platform.
+        update_action.setMenuRole(QAction.MenuRole.ApplicationSpecificRole)
+        update_action.triggered.connect(self.check_for_updates)
+        help_menu.addAction(update_action)
+        help_menu.addSeparator()
+
         about_action = QAction("About Better Claude Config…", self)
+        # Qt auto-assigns AboutRole to actions whose text starts with "About",
+        # which moves this into the application menu on macOS. That is the
+        # right home there -- state it explicitly rather than inheriting it by
+        # accident, since the behaviour is invisible from this call site.
+        about_action.setMenuRole(QAction.MenuRole.AboutRole)
         about_action.triggered.connect(self._show_about)
         help_menu.addAction(about_action)
 
+    def _show_update_notice(self, notice: dict):
+        """Surface an available update where it survives the next click."""
+        url = notice["url"]
+        self.update_banner.show_notice(
+            notice["text"],
+            action_label="Open releases page",
+            on_action=lambda: QDesktopServices.openUrl(QUrl(url)),
+        )
+
+    def check_for_updates(self):
+        """Menu-driven check. Unlike the startup check this is never throttled
+        and always reports back -- the user asked, so silence would read as a
+        broken button."""
+        self.status.setText("Checking for updates…")
+        self._menu_update_worker = UpdateCheckWorker()
+        self._menu_update_worker.done.connect(self._on_menu_update_checked)
+        self._menu_update_worker.start()
+
+    def _on_menu_update_checked(self, release: dict | None):
+        self._menu_update_worker = None
+        if release is None:
+            self.status.setText("Couldn't check for updates (offline?).")
+            return
+        QSettings("BCC", "BetterClaudeConfig").setValue("update/lastCheck", time.time())
+        notice = core.update_notice(core.__version__, release)
+        if notice:
+            self._show_update_notice(notice)
+            self.status.setText(f"Update available: {notice['version']}")
+        else:
+            self.update_banner.hide()
+            self.status.setText(f"You're up to date ({core.__version__}).")
+
+    def _set_theme(self, setting: str):
+        """Persist the theme choice and repaint the running window."""
+        QSettings("BCC", "BetterClaudeConfig").setValue("ui/theme", setting)
+        app = QApplication.instance()
+        if app is None:  # pragma: no cover - only in a headless test harness
+            return
+        app.setStyleSheet(theme_stylesheet_for(app, setting))
+        # The global stylesheet covers most of the UI, but the inline
+        # setStyleSheet calls (status dots, warning labels, update banner) only
+        # pick up the new palette when their widget next renders -- so re-render
+        # them now rather than leaving dark-on-light text behind.
+        self._repaint_themed_widgets()
+
+    def _repaint_themed_widgets(self):
+        """Re-run the inline-styled bits after a palette change."""
+        self.status.setStyleSheet(f"color: {MUTED};")
+        idx = self._current_index()
+        self._refresh_tables(select_index=idx if idx >= 0 else -1)
+        self._update_status(saved=False)
+
     def _show_about(self):
         AboutDialog(self).exec()
 
@@ -1610,10 +1788,9 @@ class MainWindow(QMainWindow):
         if release is None:
             return  # offline/failed check: don't advance lastCheck, allow retry
         QSettings("BCC", "BetterClaudeConfig").setValue("update/lastCheck", time.time())
-        if core.is_newer_version(core.__version__, release["version"]):
+        notice = core.update_notice(core.__version__, release)
-            self.status.setText(
+        if notice:
-                f"Update available: {release['version']}  ·  Help ▸ About to view it."
+            self._show_update_notice(notice)
-            )
 
     # --- layout persistence ---------------------------------------------- #
     def _restore_layout(self):
@@ -1939,9 +2116,21 @@ class MainWindow(QMainWindow):
                 return
             self.full_config = cfg
             repaired = True
+        # extract_servers tolerates malformed entries rather than raising (#72),
+        # but keep it inside the guard: a load failure must leave the previously
+        # loaded profile intact instead of half-swapping the window's state.
+        try:
+            servers = core.extract_servers(self.full_config)
+        except Exception as exc:  # pragma: no cover - defence in depth
+            QMessageBox.critical(
+                self,
+                "Could not read config",
+                f"{profile.path}\n\nThe server list couldn't be read: {exc}",
+            )
+            return
         self._loaded_stat = core.config_fingerprint(profile.path)
         self.current_profile = profile
-        self.servers = core.extract_servers(self.full_config)
+        self.servers = servers
         self.dirty = False
         self.restart_btn.hide()
         self._undo_stack.clear()
@@ -2264,7 +2453,7 @@ class MainWindow(QMainWindow):
         entry = self.servers[idx]
         old_name = entry.name
         entry.name = self.editor.current_name()
-        entry.data = self.editor.dump_data()
+        entry.set_data(self.editor.dump_data())
         # The server stays in its section (enable state unchanged), so update
         # its existing row in place rather than re-rendering.
         # An edit invalidates any cached "Test all" result -- the server that
@@ -2358,7 +2547,7 @@ class MainWindow(QMainWindow):
                 QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
             )
             if ans == QMessageBox.StandardButton.Yes:
-                self.servers[existing[name]].data = data
+                self.servers[existing[name]].set_data(data)
                 return False, True
             name = core.resolve_name_collision(name, {s.name for s in self.servers})
         self.servers.append(core.ServerEntry(name, data, True))
@@ -2433,6 +2622,12 @@ class MainWindow(QMainWindow):
             self.save_btn.setEnabled(False)
             return False
         lint_warnings = core.lint_servers(self.servers)
+        # ${VAR} references are only meaningful if the target client expands
+        # them -- Claude Desktop doesn't, so the same config is fine in one
+        # profile and broken in another (#76). Report against the loaded one.
+        for entry in self.servers:
+            for warning in core.env_ref_warnings(entry.data, self.current_profile):
+                lint_warnings.append(f"'{entry.name}': {warning}")
         if lint_warnings:
             self.validation_lbl.setText(f"⚠ {lint_warnings[0]}")
             self.validation_lbl.setStyleSheet(f"color: {WARN};")
@@ -2478,6 +2673,11 @@ class MainWindow(QMainWindow):
                 except Exception as e:
                     QMessageBox.critical(self, "Reload failed", str(e))
                     return
+                # The reload above is the on-disk truth for everything the user
+                # didn't touch -- but it also wipes BCC-authored keys the user
+                # changed in this session (named sets), which apply_servers
+                # doesn't write. Carry them over before saving (#73).
+                contested = core.carry_owned_keys(self.full_config, fresh)
                 core.apply_servers(fresh, self.servers)
                 try:
                     backup = core.write_config(self.current_profile.path, fresh)
@@ -2490,8 +2690,13 @@ class MainWindow(QMainWindow):
                 self.dirty = False
                 self.save_btn.setEnabled(False)
                 bnote = f"  ·  backup: {backup.name}" if backup else "  ·  (new file)"
+                cnote = (
+                    f"  ·  kept your {', '.join(contested)} (the file on disk had a different copy)"
+                    if contested
+                    else ""
+                )
                 self.status.setText(
-                    f"Merged & saved {self.current_profile.path}{bnote}"
+                    f"Merged & saved {self.current_profile.path}{bnote}{cnote}"
                     f"  ·  Restart {self.current_profile.label} to apply."
                 )
                 self._offer_restart_button()
@@ -2649,6 +2854,33 @@ class MainWindow(QMainWindow):
         e.accept()
 
 
+def system_is_dark(app: QApplication) -> bool:
+    """Whether the desktop is currently using a dark appearance.
+
+    Read from the style's own window colour rather than per-platform APIs --
+    Qt has already resolved the OS appearance by the time it builds the
+    default palette, so this works the same on all three platforms.
+    """
+    try:
+        return app.palette().color(QPalette.ColorRole.Window).lightness() < 128
+    except Exception:  # pragma: no cover - defensive; never block startup on theming
+        return True
+
+
+def stored_theme_setting() -> str:
+    """The user's theme choice, defaulting to following the system."""
+    value = QSettings("BCC", "BetterClaudeConfig").value("ui/theme", core.THEME_SYSTEM)
+    return value if value in core.THEME_CHOICES else core.THEME_SYSTEM
+
+
+def theme_stylesheet_for(app: QApplication, setting: str | None = None) -> str:
+    """Resolve setting + OS appearance into a palette, apply it, return the QSS."""
+    if setting is None:
+        setting = stored_theme_setting()
+    theme = core.resolve_theme(setting, system_is_dark(app))
+    return apply_palette(core.palette_for(theme))
+
+
 def main():
     if sys.platform == "win32":
         # Without an explicit AppUserModelID, Windows taskbar groups the app
@@ -2667,7 +2899,7 @@ def main():
     icon = _app_icon()
     if not icon.isNull():
         app.setWindowIcon(icon)
-    app.setStyleSheet(STYLESHEET)
+    app.setStyleSheet(theme_stylesheet_for(app))
     win = MainWindow()
     win.show()
     sys.exit(app.exec())

bcc_core.py

@@ -15,6 +15,7 @@ from __future__ import annotations
 
 import base64
 import contextlib
+import copy
 import difflib
 import functools
 import glob
@@ -49,6 +50,12 @@ DISABLED_KEY = "_disabledMcpServers"
 # parks the rest under DISABLED_KEY.
 SETS_KEY = "_bccServerSets"
 
+# Top-level keys BCC itself authors. They live in the client's config file, but
+# BCC is their owner, so on a stale-file merge the in-memory copy wins over the
+# on-disk one (see `carry_owned_keys`). Any future BCC-authored key belongs
+# here -- forgetting to add one is exactly how #73 happened.
+BCC_OWNED_KEYS = (SETS_KEY,)
+
 BACKUP_DIRNAME = ".bcc_backups"
 MAX_BACKUPS = 15
 
@@ -163,6 +170,39 @@ def fetch_latest_release(timeout: float = 4.0) -> dict | None:
     return {"version": tag, "url": payload.get("html_url") or RELEASES_URL}
 
 
+def update_notice(
+    current: str, release: dict | None, url_fallback: str = RELEASES_URL
+) -> dict | None:
+    """Decide whether to tell the user about a release, and what to say.
+
+    Returns {"version", "text", "url"} when `release` is newer than `current`,
+    or None when it isn't, when the check failed, or when the payload is
+    malformed. Kept here rather than in the GUI so the wording and the
+    should-we-notify decision are testable -- bcc.py can't be imported by the
+    test suite, which has no PySide6.
+
+    The text deliberately names no menu path. The old status-line notice read
+    "Help > About to view it", which is wrong on macOS: Qt relocates the About
+    action into the application menu (#79). A notice that carries its own
+    action can't drift out of sync with the platform.
+    """
+    if not isinstance(release, dict):
+        return None
+    version = release.get("version")
+    if not version or not isinstance(version, str):
+        return None
+    if not is_newer_version(current, version):
+        return None
+    # Tags carry a "v" prefix and __version__ doesn't; render both the same way
+    # so the notice doesn't read "Version v1.3.0 ... you're running 1.2.0".
+    shown = version.lstrip("vV")
+    return {
+        "version": version,
+        "text": f"Version {shown} is available. You're running {current.lstrip('vV')}.",
+        "url": release.get("url") or url_fallback,
+    }
+
+
 # --------------------------------------------------------------------------- #
 # Data model
 # --------------------------------------------------------------------------- #
@@ -178,16 +218,195 @@ class Profile:
         self.path = Path(self.path)
 
 
+class _NoRaw:
+    """Sentinel for ServerEntry.raw.
+
+    `None` can't do this job: `{"mcpServers": {"foo": null}}` is legal JSON and
+    a real malformed-entry case, so None has to mean "the config said null",
+    not "there was nothing here".
+    """
+
+    __slots__ = ()
+
+    def __repr__(self) -> str:  # keeps ServerEntry reprs readable in test output
+        return "<no raw>"
+
+
+NO_RAW = _NoRaw()
+
+
 @dataclass
 class ServerEntry:
+    """One server definition.
+
+    `data` is always a dict so every consumer can treat it as one. When the
+    config held something that wasn't a JSON object for this server (a string,
+    a number, a list -- all legal JSON, all wrong here), `data` is empty and
+    the original value is preserved verbatim in `raw` so Save round-trips it
+    instead of silently deleting the user's line. `lint_servers` surfaces it.
+    `raw` defaults to the NO_RAW sentinel rather than None, because a config
+    value of literal `null` is itself a malformed entry worth preserving.
+
+    Assigning `data` means the user replaced the definition through the editor,
+    which retires `raw` -- use `set_data` so that can't be forgotten.
+    """
+
     name: str
     data: dict
     enabled: bool = True
+    raw: object = NO_RAW
 
     @property
     def kind(self) -> str:
         return "remote" if "url" in self.data and "command" not in self.data else "stdio"
 
+    @property
+    def malformed(self) -> bool:
+        """True when the config value for this server wasn't a JSON object."""
+        return self.raw is not NO_RAW
+
+    def set_data(self, data: dict) -> None:
+        """Replace the definition from the editor, clearing any malformed original."""
+        self.data = data
+        self.raw = NO_RAW
+
+    def config_value(self):
+        """What to write back to the config: the edited dict, or the untouched
+        malformed original when the user never edited it."""
+        return self.data if self.raw is NO_RAW else self.raw
+
+
+# --------------------------------------------------------------------------- #
+# Theming (issue #75)
+# --------------------------------------------------------------------------- #
+THEME_SYSTEM = "system"
+THEME_LIGHT = "light"
+THEME_DARK = "dark"
+THEME_CHOICES = (THEME_SYSTEM, THEME_LIGHT, THEME_DARK)
+
+
+@dataclass(frozen=True)
+class Palette:
+    """Every colour the UI draws with.
+
+    Deliberately exhaustive: the stylesheet used to inline a handful of
+    near-black literals (`#1a1205` for text on the accent, `#202229` for the
+    disabled table, `#16181d` for the diagnostics pane), which is fine while
+    there's one theme and invisible breakage the moment there are two. Each
+    gets a slot here so a light palette can't silently inherit a dark value.
+    """
+
+    name: str
+    accent: str
+    accent_dim: str
+    bg: str
+    panel: str
+    panel_2: str
+    text: str
+    muted: str
+    border: str
+    good: str
+    bad: str
+    warn: str
+    remote: str
+    on_accent: str  # text drawn on top of an accent fill
+    disabled_bg: str  # the parked-servers table
+    mono_bg: str  # diagnostics / log panes
+    selection_text: str
+
+
+# The shipping theme through v1.3.0. These values are carried over verbatim --
+# adding a light theme must not restyle the dark one.
+DARK_PALETTE = Palette(
+    name="dark",
+    accent="#f97316",
+    accent_dim="#c2570b",
+    bg="#1b1d23",
+    panel="#23262e",
+    panel_2="#2b2f39",
+    text="#e7e9ee",
+    muted="#9aa0ad",
+    border="#3a3f4b",
+    good="#4ade80",
+    bad="#f87171",
+    warn="#fbbf24",
+    remote="#60a5fa",
+    on_accent="#1a1205",
+    disabled_bg="#202229",
+    mono_bg="#16181d",
+    selection_text="#ffffff",
+)
+
+# The semantic colours are NOT the dark ones lightened. #4ade80 / #fbbf24 sit
+# around 1.7:1 against white -- illegible. These are darkened to clear 4.5:1,
+# which `test_light_palette_meets_contrast` enforces so nobody "tidies" them
+# back toward the dark hues later.
+LIGHT_PALETTE = Palette(
+    name="light",
+    accent="#c2410c",
+    accent_dim="#9a3412",
+    bg="#f6f7f9",
+    panel="#ffffff",
+    panel_2="#eef0f4",
+    text="#1b1d23",
+    muted="#5c6270",
+    border="#d3d7de",
+    good="#15803d",
+    bad="#b91c1c",
+    warn="#a16207",
+    remote="#1d4ed8",
+    on_accent="#ffffff",
+    disabled_bg="#e9ebef",
+    mono_bg="#f0f2f5",
+    selection_text="#ffffff",
+)
+
+PALETTES = {DARK_PALETTE.name: DARK_PALETTE, LIGHT_PALETTE.name: LIGHT_PALETTE}
+
+
+def resolve_theme(setting: str, system_is_dark: bool) -> str:
+    """Map a stored theme setting + the OS appearance onto a concrete palette name.
+
+    Anything unrecognised (a hand-edited QSettings value, a setting written by
+    a future version) falls back to following the system rather than to a
+    fixed theme -- the user's desktop is the better guess.
+    """
+    if setting == THEME_DARK:
+        return THEME_DARK
+    if setting == THEME_LIGHT:
+        return THEME_LIGHT
+    return THEME_DARK if system_is_dark else THEME_LIGHT
+
+
+def palette_for(theme: str) -> Palette:
+    """Concrete palette by name; unknown names fall back to dark (the historical look)."""
+    return PALETTES.get(theme, DARK_PALETTE)
+
+
+def _hex_to_rgb(value: str) -> tuple[int, int, int]:
+    v = value.lstrip("#")
+    if len(v) == 3:
+        v = "".join(ch * 2 for ch in v)
+    return int(v[0:2], 16), int(v[2:4], 16), int(v[4:6], 16)
+
+
+def relative_luminance(color: str) -> float:
+    """WCAG relative luminance for a #rrggbb colour."""
+
+    def chan(c: int) -> float:
+        srgb = c / 255.0
+        return srgb / 12.92 if srgb <= 0.04045 else ((srgb + 0.055) / 1.055) ** 2.4
+
+    r, g, b = (chan(c) for c in _hex_to_rgb(color))
+    return 0.2126 * r + 0.7152 * g + 0.0722 * b
+
+
+def contrast_ratio(fg: str, bg: str) -> float:
+    """WCAG contrast ratio between two #rrggbb colours (1.0 to 21.0)."""
+    a, b = relative_luminance(fg), relative_luminance(bg)
+    lighter, darker = max(a, b), min(a, b)
+    return (lighter + 0.05) / (darker + 0.05)
+
 
 # --------------------------------------------------------------------------- #
 # Discovery
@@ -452,13 +671,30 @@ def repair_config_file(path: str | os.PathLike) -> tuple[dict, list[str], str]:
     return obj, notes, pretty
 
 
+def _server_entry(name: str, data, enabled: bool) -> ServerEntry:
+    """Build a ServerEntry, tolerating a value that isn't a JSON object.
+
+    A hand-edited config can legally hold `{"mcpServers": {"foo": "oops"}}` --
+    valid JSON, wrong shape. Calling dict() on that raises, which used to take
+    the whole load down before the linter ever got a look at it (#72). Keep the
+    original instead and let the linter report it.
+    """
+    if isinstance(data, dict):
+        return ServerEntry(name=name, data=dict(data), enabled=enabled)
+    return ServerEntry(name=name, data={}, enabled=enabled, raw=data)
+
+
 def extract_servers(cfg: dict) -> list[ServerEntry]:
-    """Pull enabled (`mcpServers`) and disabled (`_disabledMcpServers`) servers."""
+    """Pull enabled (`mcpServers`) and disabled (`_disabledMcpServers`) servers.
+
+    Never raises on a structurally-odd config -- malformed entries come back as
+    empty-data entries carrying their original value (see `_server_entry`).
+    """
     out: list[ServerEntry] = []
     for name, data in (cfg.get("mcpServers") or {}).items():
-        out.append(ServerEntry(name=name, data=dict(data), enabled=True))
+        out.append(_server_entry(name, data, True))
     for name, data in (cfg.get(DISABLED_KEY) or {}).items():
-        out.append(ServerEntry(name=name, data=dict(data), enabled=False))
+        out.append(_server_entry(name, data, False))
     return out
 
 
@@ -550,8 +786,8 @@ def apply_servers(cfg: dict, servers: list[ServerEntry]) -> dict:
     Write the server list back into `cfg` in place, preserving every other key
     and the position of `mcpServers`. Returns the same dict for convenience.
     """
-    enabled = {s.name: s.data for s in servers if s.enabled}
+    enabled = {s.name: s.config_value() for s in servers if s.enabled}
-    disabled = {s.name: s.data for s in servers if not s.enabled}
+    disabled = {s.name: s.config_value() for s in servers if not s.enabled}
 
     cfg["mcpServers"] = enabled  # replaces value if key existed; appends otherwise
     if disabled:
@@ -564,6 +800,34 @@ def apply_servers(cfg: dict, servers: list[ServerEntry]) -> dict:
 # --------------------------------------------------------------------------- #
 # Write (atomic, with rotating backups)
 # --------------------------------------------------------------------------- #
+def carry_owned_keys(local_cfg: dict, fresh_cfg: dict) -> list[str]:
+    """Carry BCC-authored top-level keys from `local_cfg` onto `fresh_cfg`.
+
+    Used by the stale-file "Merge & save" path, which reloads the file from
+    disk and re-applies the user's server edits. That reload used to drop
+    anything BCC owns but `apply_servers` doesn't write -- named server sets
+    vanished without a word (#73). BCC owns these keys, so the in-memory copy
+    wins; mutates `fresh_cfg` in place.
+
+    Returns the keys where the on-disk copy differed and was overwritten, so
+    the caller can tell the user something was actually contested rather than
+    merely carried across.
+
+    Deliberately one-directional: a key absent locally is left alone on disk.
+    We can't tell "user deleted their last set" from "user never had sets and
+    another machine just added some", and silently deleting someone else's
+    data is the worse of the two failures.
+    """
+    conflicts: list[str] = []
+    for key in BCC_OWNED_KEYS:
+        if key not in local_cfg:
+            continue
+        if key in fresh_cfg and fresh_cfg[key] != local_cfg[key]:
+            conflicts.append(key)
+        fresh_cfg[key] = copy.deepcopy(local_cfg[key])
+    return conflicts
+
+
 def _make_backup(path: Path) -> Path:
     bdir = path.parent / BACKUP_DIRNAME
     bdir.mkdir(exist_ok=True)
@@ -629,13 +893,28 @@ def backup_label(backup_path: Path | str) -> str:
     return f"{ts[:4]}-{ts[4:6]}-{ts[6:8]}  {ts[9:11]}:{ts[11:13]}:{ts[13:]}"
 
 
+def should_mask_value(key: str, value) -> bool:
+    """Whether an env/header value should be masked for display.
+
+    A ${VAR} reference is NOT a secret -- it's a pointer to one, and it's the
+    thing we want users to adopt. Masking it to dots would make a reference
+    indistinguishable from a stored credential, hiding exactly the distinction
+    that makes the feature worth using (#76).
+    """
+    if not is_secret_key(key):
+        return False
+    return not is_env_ref(value) if isinstance(value, str) else True
+
+
 def _redact_server_data(data: dict) -> dict:
     """Return a copy of a server definition with secrets masked for display."""
     out = dict(data)
     if "args" in out:
         out["args"] = redact_args(list(out["args"] or []))
     if "env" in out:
-        out["env"] = {k: (MASK if is_secret_key(k) else v) for k, v in (out["env"] or {}).items()}
+        out["env"] = {
+            k: (MASK if should_mask_value(k, v) else v) for k, v in (out["env"] or {}).items()
+        }
     return out
 
 
@@ -1186,6 +1465,155 @@ MASK = "••••••••"
 _EMBEDDED_CRED_RE = re.compile(r"://[^:@/\s]+:[^:@/\s]+@")
 
 
+# --------------------------------------------------------------------------- #
+# Environment-variable references (issue #76)
+#
+# Claude Code expands ${VAR} and ${VAR:-default} itself, in command, args, env,
+# url and headers. So BCC does NOT expand these on write -- resolving them into
+# the file would put the secret back on disk, which is the whole thing the user
+# is avoiding, and would defeat a feature the client already implements. BCC
+# authors, validates and warns.
+#
+# Claude Desktop has no documented support, so the same text there is passed to
+# the server literally. That makes this a per-client capability, not a global
+# one -- see client_expands_env_refs().
+# --------------------------------------------------------------------------- #
+# ${NAME} or ${NAME:-default}. Names follow the shell convention (letter or
+# underscore first) so a bare "${}" or "${1}" isn't mistaken for a reference.
+_ENV_REF_RE = re.compile(r"\$\{([A-Za-z_][A-Za-z0-9_]*)(?::-([^}]*))?\}")
+
+# The five fields Claude Code documents as expansion sites.
+ENV_REF_FIELDS = ("command", "args", "env", "url", "headers")
+
+
+class EnvRef(NamedTuple):
+    """One ${VAR} / ${VAR:-default} occurrence found in a server definition."""
+
+    name: str
+    default: str | None
+    field: str  # which of ENV_REF_FIELDS it was found in
+
+    @property
+    def has_default(self) -> bool:
+        return self.default is not None
+
+
+def find_env_refs(text: str, field: str = "") -> list[EnvRef]:
+    """Every ${VAR} / ${VAR:-default} reference in a single string."""
+    if not isinstance(text, str):
+        return []
+    return [EnvRef(m.group(1), m.group(2), field) for m in _ENV_REF_RE.finditer(text)]
+
+
+def is_env_ref(value: str) -> bool:
+    """True when the value contains at least one ${VAR} reference.
+
+    Used to keep placeholders OUT of secret masking: `${API_KEY}` under a
+    secret-looking key is a reference, not a secret, and masking it to dots
+    would hide the one distinction the user needs to see.
+    """
+    return bool(find_env_refs(value))
+
+
+def server_env_refs(data: dict) -> list[EnvRef]:
+    """Every env reference in a server definition, tagged with its field.
+
+    Only inspects the fields Claude Code actually expands; a ${VAR} written
+    into some other key is not a reference and shouldn't be reported as one.
+    """
+    out: list[EnvRef] = []
+    if not isinstance(data, dict):
+        return out
+    for field in ENV_REF_FIELDS:
+        value = data.get(field)
+        if isinstance(value, str):
+            out.extend(find_env_refs(value, field))
+        elif isinstance(value, list):
+            for item in value:
+                out.extend(find_env_refs(item, field))
+        elif isinstance(value, dict):
+            for v in value.values():
+                out.extend(find_env_refs(v, field))
+    return out
+
+
+def expand_env_refs(text: str, environ: dict | None = None) -> str:
+    """Expand ${VAR} / ${VAR:-default} the way Claude Code documents it.
+
+    Provided for previewing what the client will do -- BCC never writes the
+    expanded form back to the config. Unset with no default is left as the
+    literal ${VAR} text, matching Claude Code: the config still loads and the
+    unexpanded text is passed through.
+    """
+    if not isinstance(text, str):
+        return text
+    env = os.environ if environ is None else environ
+
+    def repl(m: re.Match) -> str:
+        name, default = m.group(1), m.group(2)
+        if name in env:
+            return env[name]
+        return default if default is not None else m.group(0)
+
+    return _ENV_REF_RE.sub(repl, text)
+
+
+def unresolved_env_refs(data: dict, environ: dict | None = None) -> list[EnvRef]:
+    """References that would not resolve: variable unset AND no default.
+
+    Best-effort by nature -- BCC's environment isn't necessarily the client's,
+    so this warns rather than blocks, and the warning text says so.
+    """
+    env = os.environ if environ is None else environ
+    return [r for r in server_env_refs(data) if not r.has_default and r.name not in env]
+
+
+def client_expands_env_refs(profile: Profile) -> bool:
+    """Whether the client behind `profile` expands ${VAR} itself.
+
+    Claude Code does, in command/args/env/url/headers, for both project
+    `.mcp.json` and user-scope `~/.claude.json`. Claude Desktop has no
+    documented support, so a reference there reaches the server as literal
+    text -- which surfaces as a confusing auth failure rather than an obvious
+    config error, hence the warning.
+    """
+    return not profile_targets_claude_desktop(profile)
+
+
+def env_ref_warnings(
+    data: dict, profile: Profile | None = None, environ: dict | None = None
+) -> list[str]:
+    """Advisory warnings about env references in one server definition.
+
+    Two distinct problems, deliberately worded differently:
+      - the target client won't expand them at all (Claude Desktop)
+      - the client will expand them, but a variable looks unset here
+    """
+    refs = server_env_refs(data)
+    if not refs:
+        return []
+
+    if profile is not None and not client_expands_env_refs(profile):
+        names = ", ".join(sorted({f"${{{r.name}}}" for r in refs}))
+        return [
+            f"{names} will NOT be expanded by Claude Desktop -- it has no "
+            f"documented support for variable references, so the server "
+            f"receives the literal text. Use a real value here, or move this "
+            f"server to a Claude Code config."
+        ]
+
+    missing = unresolved_env_refs(data, environ)
+    if not missing:
+        return []
+    names = ", ".join(sorted({r.name for r in missing}))
+    return [
+        f"{names} is not set in this environment and has no ':-default'. "
+        f"Claude Code will pass the reference through unexpanded. "
+        f"(Checked against BCC's environment, which may differ from the "
+        f"client's.)"
+    ]
+
+
 def is_secret_key(name: str) -> bool:
     """Does this env-var / header / flag name look like it holds a secret?"""
     return bool(_SECRET_KEY_RE.search(name or ""))
@@ -1202,17 +1630,22 @@ def redact_args(args: list[str]) -> list[str]:
       --api-key=abc123      ->  --api-key=••••••••   (inline flag=value)
       ghp_abc123            ->  ••••••••             (well-known token prefix)
     Everything else passes through untouched.
+
+    ${VAR} references are left visible: they name a secret rather than being
+    one, and hiding them would obscure the difference between "this config
+    leaks a token" and "this config points at one" (#76).
     """
     out: list[str] = []
     mask_next = False
     for a in args:
         s = str(a)
         if mask_next:
-            out.append(MASK)
             mask_next = False
+            out.append(s if is_env_ref(s) else MASK)
             continue
         if s.startswith("-") and "=" in s and is_secret_key(s.split("=", 1)[0]):
-            out.append(s.split("=", 1)[0] + "=" + MASK)
+            flag, value = s.split("=", 1)
+            out.append(f"{flag}={value}" if is_env_ref(value) else f"{flag}={MASK}")
             continue
         if s.startswith("-") and is_secret_key(s):
             out.append(s)
@@ -1239,6 +1672,11 @@ def args_secret_warning(data: dict) -> str | None:
     args = [str(a) for a in (data.get("args") or [])]
     mask_next = False
     for a in args:
+        # A ${VAR} reference is the recommended fix for this very warning --
+        # continuing to warn after the user adopts it punishes the fix (#76).
+        if is_env_ref(a):
+            mask_next = False
+            continue
         if mask_next:
             mask_next = False
             if not a.startswith("-"):
@@ -1380,9 +1818,21 @@ def lint_server(name: str, data: dict) -> list[str]:
 
 
 def lint_servers(servers: list[ServerEntry]) -> list[str]:
-    """Concatenate lint_server warnings across every entry, in order."""
+    """Concatenate lint_server warnings across every entry, in order.
+
+    Entries whose config value wasn't a JSON object at all are reported here
+    rather than in lint_server, which takes an already-dict `data` (#72).
+    """
     out: list[str] = []
     for s in servers:
+        if s.malformed:
+            nm = s.name.strip() or "(unnamed)"
+            out.append(
+                f"'{nm}': server definition is not an object "
+                f"(found {type(s.raw).__name__}) -- it is preserved as-is; "
+                f"edit it to replace it with a proper definition"
+            )
+            continue
         out.extend(lint_server(s.name, s.data))
     return out
 
@@ -2193,7 +2643,7 @@ CATALOG_DENIED_ENV_KEYS = frozenset(
 # still trust an older key: verify_catalog_signature() accepts a match
 # against ANY key in this list.
 CATALOG_PUBKEYS: list[bytes] = [
-    base64.b64decode("0s24PmkZcTT5yxNDdyTPHl5fyxArrHNPJKBjnXoQd8k="),
+    base64.b64decode("082NOwVB7uURkvfyS3+knJ+40Fk6C9unsF47+2uPKo4="),
 ]
 
 # Domain-separation prefix for the signed message. The signature covers

catalog_console.py

@@ -10,20 +10,14 @@ for data/catalog.json (issue #62).
 Flow: Load -> Review -> Sign.
 
   1. Load    -- pick a source: an open Gitea PR touching data/catalog.json,
-                the current tip of `main`, or the branch this checkout is
+                or the current tip of `main`. The Console fetches the exact
-                currently ON (or --ref names) -- the latter exists so a
+                git blob (via a local clone's git plumbing) and PINS its
-                catalog-signing-key rotation, or any other catalog change
+                blob SHA *and the ref it came from* for the rest of this
-                landed on a branch, can be reviewed and SIGNED before that
+                review pass. For a PR, the diff is against `main`; for
-                branch is ever merged, instead of merging a PR that leaves
+                `main`, the diff is against the last catalog a maintainer
-                main red and fixing it up afterwards (issue #68). The
+                actually SIGNED (the bytes covered by the current
-                Console fetches the exact git blob (via a local clone's git
+                data/catalog.json.sig), never against itself -- an empty
-                plumbing) and PINS its blob SHA *and the ref it came from*
+                diff must mean "nothing to sign", never "sign unlocked".
-                for the rest of this review pass. For a PR, the diff is
-                against `main`; for `main` or a branch, the diff is against
-                the last catalog a maintainer actually SIGNED on that same
-                ref (the bytes covered by the current data/catalog.json.sig
-                there), never against itself -- an empty diff must mean
-                "nothing to sign", never "sign unlocked".
   2. Review  -- a semantic diff (catalog_review.diff_catalogs), one card per
                 changed entry, with risk annotations
                 (catalog_review.entry_risk_findings). A registry lookup for
@@ -43,23 +37,13 @@ Flow: Load -> Review -> Sign.
                 blocking risk finding (catalog_review.sign_precondition /
                 can_sign -- the TOCTOU fix). On success, writes
                 data/catalog.json + data/catalog.json.sig and commits BOTH
-                in a single commit, then pushes to the SAME ref that was
+                in a single commit, then pushes -- so main is never red
-                reviewed (never a hardcoded "main") -- so that ref is never
+                between a catalog merge and its signature. Signing uses the
-                red between a catalog merge and its signature, whether
-                that ref is `main` or a rotation branch. Signing uses the
                 CATALOG key ONLY -- see "Two signing keys" below.
 
 The signature must be the artefact of an actual review, not a step that
 follows one. Signing IS the approval act.
 
-Confused about which key is which, or what state either is in? Run
-`python catalog_console.py keys` -- it needs no passphrase and prints a
-plain-English status report for both keys: where each private half lives,
-whether it's present, its fingerprint, whether that fingerprint matches
-what's committed in bcc_core.py / ci.yml / scripts/sign_checksums.py, and
-whether data/catalog.json.sig currently verifies -- ending with exactly
-what to run next.
-
 Two signing keys (issue #68 finding 5): the CATALOG key (offline,
 Console-only, `keygen` / `keygen --release` picks which) is the root of
 trust for what BCC executes and must never touch CI. The RELEASE key is
@@ -85,7 +69,6 @@ import urllib.error
 import urllib.request
 from dataclasses import dataclass
 from pathlib import Path
-from typing import ClassVar
 
 import bcc_core as core
 import catalog_review as review
@@ -214,89 +197,6 @@ def unlock_signing_key(passphrase: str, kind: str = "catalog") -> bytes:
     return review.decrypt_private_key(blob, passphrase)
 
 
-def _pubkey_cache_file(kind: str) -> Path:
-    assert kind in _KEY_KINDS, f"unknown key kind {kind!r}, expected one of {_KEY_KINDS}"
-    return KEY_STORAGE_DIR / f"signing_key_{kind}.pub"
-
-
-def store_public_key(pubkey: bytes, kind: str = "catalog") -> None:
-    """Cache the PUBLIC half of a signing key, in plain base64, next to its
-    encrypted private counterpart (OS keychain if available, else the file
-    cache). Public keys are not secret -- this cache exists purely so
-    `catalog_console.py keys` can report a fingerprint and compare it
-    against what's committed in source WITHOUT ever decrypting (or asking
-    for a passphrase to unlock) the private key. Called by cmd_keygen()
-    right after a keypair is generated.
-    """
-    keyring = _keyring_module()
-    pub_b64 = base64.b64encode(pubkey).decode("ascii")
-    if keyring is not None:
-        try:
-            keyring.set_password(_KEYRING_SERVICE, f"{_keyring_username(kind)}-pub", pub_b64)
-            return
-        except Exception:
-            pass  # fall through to the file-based cache
-    KEY_STORAGE_DIR.mkdir(parents=True, exist_ok=True)
-    _pubkey_cache_file(kind).write_text(pub_b64 + "\n", encoding="utf-8")
-
-
-def load_public_key(kind: str = "catalog") -> bytes | None:
-    """The cached PUBLIC key of the given `kind`, or None if no key of that
-    kind has been generated yet (or it predates public-key caching -- an
-    older keygen run that never called store_public_key). Never touches the
-    encrypted private blob and never asks for a passphrase."""
-    keyring = _keyring_module()
-    if keyring is not None:
-        try:
-            pub_b64 = keyring.get_password(_KEYRING_SERVICE, f"{_keyring_username(kind)}-pub")
-            if pub_b64:
-                return base64.b64decode(pub_b64)
-        except Exception:
-            pass
-    path = _pubkey_cache_file(kind)
-    if not path.exists():
-        return None
-    text = path.read_text(encoding="utf-8").strip()
-    if not text:
-        return None
-    try:
-        return base64.b64decode(text)
-    except ValueError:
-        return None
-
-
-def has_encrypted_key(kind: str = "catalog") -> bool:
-    """Whether a private key of this `kind` has been generated on this
-    machine -- checked WITHOUT decrypting or asking for a passphrase, so
-    `catalog_console.py keys` can report existence unconditionally."""
-    keyring = _keyring_module()
-    if keyring is not None:
-        try:
-            if keyring.get_password(_KEYRING_SERVICE, _keyring_username(kind)):
-                return True
-        except Exception:
-            pass
-    return _key_storage_file(kind).exists()
-
-
-def describe_local_key_location(kind: str) -> str:
-    """Human-readable description of where a `kind` key's PRIVATE half
-    lives on this machine, for the `keys` report and the sign-flow prompt.
-    Never the release key's CI location -- that's cmd_keys' job to append,
-    since it's true regardless of whether a local copy also exists."""
-    keyring = _keyring_module()
-    if keyring is not None:
-        try:
-            if keyring.get_password(_KEYRING_SERVICE, _keyring_username(kind)):
-                return "on this machine, in the OS keychain (encrypted, passphrase-protected)"
-        except Exception:
-            pass
-    key_file = _key_storage_file(kind)
-    if key_file.exists():
-        return f"on this machine, at {key_file} (encrypted, passphrase-protected)"
-    return "not generated yet"
-
-
 # --------------------------------------------------------------------------- #
 # git plumbing against a local clone. The clone's `origin` remote is assumed
 # to already carry credentials (the "tokened remote" every other BCC
@@ -323,40 +223,6 @@ def fetch_ref(repo_dir: Path, ref: str) -> str:
     return _git(repo_dir, "rev-parse", "FETCH_HEAD").strip()
 
 
-def current_branch(repo_dir: Path) -> str | None:
-    """The branch currently checked out at `repo_dir`, or None if it can't
-    be determined (detached HEAD, bare repo, mid-rebase, ...). This is what
-    lets the Console offer "sign against the branch I already have checked
-    out" as a source (issue #68 rotation-completability fix) without the
-    maintainer having to type the branch name -- ReviewWindow defaults to
-    it unless --ref names one explicitly.
-    """
-    try:
-        name = _git(repo_dir, "rev-parse", "--abbrev-ref", "HEAD").strip()
-    except GitError:
-        return None
-    return None if name in ("", "HEAD") else name
-
-
-def compute_own_refs(explicit_ref: str | None, detected_branch: str | None) -> list[str]:
-    """ "main" plus (if different) `explicit_ref` or `detected_branch` -- the
-    exact list of refs ReviewWindow offers as "own" sources (loadable,
-    signable, AND pushable directly, unlike a PR's read-only
-    refs/pull/<n>/head). Pure: `detected_branch` is injected (normally
-    current_branch(repo_dir)) so this ref-resolution seam -- the fix for
-    issue #68's "rotation can't complete without a red main" -- is testable
-    without git or Qt. "main" is always index 0 so a stale/absent
-    list-widget selection still defaults sanely (see ReviewWindow._on_load's
-    row-clamping, and cmd_gui/ReviewWindow.__init__ for how `explicit_ref`
-    is threaded from --ref).
-    """
-    refs = ["main"]
-    branch = explicit_ref or detected_branch
-    if branch and branch not in refs:
-        refs.append(branch)
-    return refs
-
-
 def blob_sha_at(repo_dir: Path, commit: str, path: str) -> str:
     """The git blob SHA of `path` as it exists at `commit`. This is what
     gets pinned at review-start and re-checked immediately before signing
@@ -417,48 +283,17 @@ def last_signed_catalog_raw(repo_dir: Path, commit: str) -> bytes | None:
     return review.find_last_signed_catalog_raw(candidates, sig_bytes, core.CATALOG_PUBKEYS)
 
 
-def catalog_signature_valid_at(repo_dir: Path, commit: str, raw: bytes) -> bool:
-    """Whether data/catalog.json.sig as of `commit` verifies `raw` against
-    the CURRENTLY-TRUSTED bcc_core.CATALOG_PUBKEYS.
-
-    False whenever there is no .sig file, or the .sig exists but was
-    produced by a key that is not (or no longer) in CATALOG_PUBKEYS -- most
-    notably right after a catalog signing-key rotation (issue #68 finding 5
-    follow-up), when the committed .sig was produced by the now-retired old
-    key. This is the rotation-detection primitive ReviewWindow._on_load
-    uses to decide whether to enter re-attestation mode
-    (review.start_review(..., reattest=True)) instead of the ordinary
-    diff-against-last-signed path.
-
-    Delegates to bcc_core.verify_catalog_signature -- never reimplemented,
-    per this module's docstring ("one source of truth").
-    """
-    try:
-        sig_sha = blob_sha_at(repo_dir, commit, SIG_PATH)
-    except GitError:
-        return False
-    sig_bytes = blob_bytes(repo_dir, sig_sha)
-    return core.verify_catalog_signature(raw, sig_bytes, core.CATALOG_PUBKEYS)
-
-
 def commit_and_push_signed_catalog(
     repo_dir: Path, raw_bytes: bytes, signature: bytes, *, branch: str = "main"
 ) -> str:
     """Write data/catalog.json + data/catalog.json.sig and commit BOTH in a
     single commit, then push to `branch`. Returns the new commit SHA.
 
-    `branch` MUST be the same ref that was actually reviewed
-    (ReviewWindow._on_sign passes `session.loaded_ref`, never a hardcoded
-    "main" -- issue #68 completability fix): a catalog change reviewed on a
-    branch has to be signed and pushed to THAT branch so the branch itself
-    is never red, rather than landing the signature on main after a merge.
-
     This is deliberate: if signing happened in a commit AFTER the catalog
-    merge, `branch` would be red (payload present, signature missing)
+    merge, main would be red (payload present, signature missing) between
-    between the catalog merge and its signing commit. Routine red branches
+    every catalog merge and its signing commit. Routine red-main trains
-    train exactly the alarm fatigue this whole design exists to prevent.
+    exactly the alarm fatigue this whole design exists to prevent. Emitting
-    Emitting one commit with both files means `branch` is never in that
+    one commit with both files means main is never in that state.
-    state -- whether `branch` is main or a rotation-in-progress branch.
     """
     _git(repo_dir, "checkout", branch)
     _git(repo_dir, "pull", "--ff-only", "origin", branch)
@@ -648,76 +483,14 @@ def registry_fetcher(ref: review.PackageRef) -> dict | None:
     return None
 
 
-# --------------------------------------------------------------------------- #
-# Key status ("keys" command, issue #62/#68 follow-up: "make key handling
-# comprehensible"). File I/O only -- the actual status/report logic is pure
-# and lives in catalog_review (key_status / render_key_status_report), so
-# it's unit-testable without touching disk. These wrappers read the THREE
-# places a signing key's public half is expected to be committed, from
-# `repo_dir`'s working tree, so `keys` reports on whatever ref/branch is
-# actually checked out there (never this process's own sys.path import).
-# --------------------------------------------------------------------------- #
-
-
-def read_catalog_pubkeys_from_source(repo_dir: Path) -> list[bytes]:
-    path = repo_dir / "bcc_core.py"
-    if not path.exists():
-        return []
-    return review.extract_pubkey_list_literal(path.read_text(encoding="utf-8"), "CATALOG_PUBKEYS")
-
-
-def read_release_pubkeys_from_source(repo_dir: Path) -> list[bytes]:
-    path = repo_dir / "scripts" / "sign_checksums.py"
-    if not path.exists():
-        return []
-    return review.extract_pubkey_list_literal(path.read_text(encoding="utf-8"), "RELEASE_PUBKEYS")
-
-
-def read_ci_trust_anchor_pubkeys(repo_dir: Path) -> list[bytes]:
-    path = repo_dir / ".github" / "workflows" / "ci.yml"
-    if not path.exists():
-        return []
-    pubkey = review.extract_ci_trust_anchor_pubkey(path.read_text(encoding="utf-8"))
-    return [pubkey] if pubkey is not None else []
-
-
-def catalog_sig_status_on_disk(repo_dir: Path, committed_catalog_pubkeys: list[bytes]) -> str:
-    """ "valid" / "invalid" / "missing" for data/catalog.json.sig as it sits
-    in `repo_dir`'s WORKING TREE right now (not a git ref -- the `keys`
-    command deliberately reports on-disk state, which is what "the current
-    checked-out branch" concretely means and avoids a network fetch just to
-    print a status line). Verified against `committed_catalog_pubkeys`
-    (whatever bcc_core.py on this same working tree currently says), not
-    the running process's own bcc_core import, so this stays correct no
-    matter which ref/branch happens to be checked out.
-    """
-    catalog_path = repo_dir / CATALOG_PATH
-    sig_path = repo_dir / SIG_PATH
-    if not catalog_path.exists() or not sig_path.exists():
-        return "missing"
-    raw = catalog_path.read_bytes()
-    sig = sig_path.read_bytes()
-    if core.verify_catalog_signature(raw, sig, committed_catalog_pubkeys):
-        return "valid"
-    return "invalid"
-
-
 # --------------------------------------------------------------------------- #
 # GUI (PySide6). Everything above this line has no Qt dependency and is
 # exercised by tests/test_catalog_review.py; everything below is a thin
 # shell that calls into it.
 # --------------------------------------------------------------------------- #
 
-# PySide6 is imported defensively: `keygen`, `show-seed-b64`, and `keys`
+from PySide6.QtCore import Qt, QThread, Signal  # noqa: E402
-# (the commands a maintainer runs most often, and the ones this file's
+from PySide6.QtWidgets import (  # noqa: E402
-# tests/py_compile-only CI environment can exercise) have no GUI dependency
-# at all and must keep working even somewhere PySide6 isn't installed or
-# won't import (e.g. no system Qt libs). Only `gui` needs it -- cmd_gui()
-# checks _PYSIDE6_AVAILABLE and fails with a clear message instead of an
-# ImportError stack trace if it's missing.
-try:
-    from PySide6.QtCore import Qt, QThread, Signal
-    from PySide6.QtWidgets import (
     QApplication,
     QCheckBox,
     QDialog,
@@ -736,15 +509,7 @@ try:
     QVBoxLayout,
     QWidget,
 )
-except ImportError as _pyside6_exc:  # pragma: no cover - only hit where PySide6 is absent
-    _PYSIDE6_IMPORT_ERROR: str | None = str(_pyside6_exc)
-else:
-    _PYSIDE6_IMPORT_ERROR = None
 
-_PYSIDE6_AVAILABLE = _PYSIDE6_IMPORT_ERROR is None
-
-
-if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where PySide6 is absent
 
 def plain_label(text: object) -> QLabel:
     """A QLabel guaranteed to render `text` as plain text, never HTML.
@@ -762,8 +527,10 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
     label.setWordWrap(True)
     return label
 
+
 _SEVERITY_PREFIX = {"blocking": "✖ BLOCKING", "warning": "⚠ WARNING", "info": "ℹ INFO"}
 
+
 class RegistryLookupWorker(QThread):
     """Off-UI-thread registry lookups, mirroring bcc.py's ConnTester/
     SpawnTester pattern. Never blocks the review UI on a slow/dead network."""
@@ -782,6 +549,7 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
         ]
         self.done.emit(results)
 
+
 class EntryCard(QWidget):
     """One changed catalog entry: the diff, risk findings, and the
     acknowledge checkbox that gates Sign. `command`/`args` are rendered
@@ -893,24 +661,15 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
         self.registry_label.setText(html.escape(text))
         self.registry_label.setTextFormat(Qt.PlainText)
 
+
 class PassphraseDialog(QDialog):
-        """Prompts for a signing key's passphrase.
+    def __init__(self, prompt: str, parent=None):
-
-        `prompt` must say plainly WHICH key (CATALOG or RELEASE) is about to be
-        unlocked, and its fingerprint when known -- issue #62/#68 follow-up: a
-        maintainer must see which key he's about to type a passphrase for
-        BEFORE typing it, not infer it from context. This is the exact ambiguity
-        that led to a private key being pasted into a chat window.
-        """
-
-        def __init__(self, prompt: str, window_title: str = "Signing key passphrase", parent=None):
         super().__init__(parent)
-            self.setWindowTitle(window_title)
+        self.setWindowTitle("Signing key passphrase")
         layout = QFormLayout(self)
-            layout.addRow(plain_label(prompt))
         self.edit = QLineEdit()
         self.edit.setEchoMode(QLineEdit.EchoMode.Password)
-            layout.addRow("Passphrase:", self.edit)
+        layout.addRow(prompt, self.edit)
         buttons = QDialogButtonBox(
             QDialogButtonBox.StandardButton.Ok | QDialogButtonBox.StandardButton.Cancel
         )
@@ -921,26 +680,14 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
     def passphrase(self) -> str:
         return self.edit.text()
 
-    class ReviewWindow(QMainWindow):
-        #: Placeholder empty catalog used when there is nothing to diff against
-        #: yet (no prior signature, or a key rotation invalidated the old one).
-        _EMPTY_CATALOG: ClassVar[dict] = {"schema": 1, "version": 0, "servers": []}
 
-        def __init__(self, repo_dir: Path, ref: str | None = None):
+class ReviewWindow(QMainWindow):
+    def __init__(self, repo_dir: Path):
         super().__init__()
         self.repo_dir = repo_dir
         self.session: review.ReviewSession | None = None
         self.cards: dict[str, EntryCard] = {}
 
-            # "Own" refs this clone can load/diff/sign+push against directly --
-            # issue #68 rotation-completability fix. "main" is always offered;
-            # if the checkout is on a different branch (or --ref names one
-            # explicitly), that branch is offered too, so a rotation in
-            # progress on a branch can be reviewed, signed, and pushed to ITS
-            # OWN ref -- completing the rotation before merge, never forcing a
-            # red main in between. See _load_own_ref() / _on_sign().
-            self._own_refs = self._compute_own_refs(ref)
-
         self.setWindowTitle("BCC Catalog Console -- maintainer-only, never shipped")
         central = QWidget()
         self.setCentralWidget(central)
@@ -948,13 +695,7 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
 
         top = QHBoxLayout()
         self.source_list = QListWidget()
-            for own_ref in self._own_refs:
+        self.source_list.addItem(QListWidgetItem("main (current tip)"))
-                label = (
-                    f"{own_ref} (current tip)"
-                    if own_ref == "main"
-                    else f"{own_ref} (current branch)"
-                )
-                self.source_list.addItem(QListWidgetItem(label))
         top.addWidget(self.source_list, 1)
 
         side = QVBoxLayout()
@@ -968,22 +709,6 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
         top.addLayout(side)
         root.addLayout(top)
 
-            # KEY-ROTATION RE-ATTESTATION BANNER (issue #68 finding 5 follow-up).
-            # Hidden until _on_load() detects that the loaded catalog's
-            # signature does NOT verify under the currently-trusted
-            # bcc_core.CATALOG_PUBKEYS (catalog_signature_valid_at()) -- most
-            # commonly, right after the maintainer rotates the catalog signing
-            # key. This mode must NEVER be entered silently: this banner is the
-            # only thing standing between "every entry needs re-review" and a
-            # maintainer wondering why the diff view suddenly shows 19
-            # "added" entries with no explanation.
-            self.reattest_banner = plain_label("")
-            self.reattest_banner.setStyleSheet(
-                "background-color: #c62828; color: white; font-weight: bold; padding: 8px;"
-            )
-            self.reattest_banner.setVisible(False)
-            root.addWidget(self.reattest_banner)
-
         self.scroll = QScrollArea()
         self.scroll.setWidgetResizable(True)
         self.card_container = QWidget()
@@ -1003,66 +728,41 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
         self._prs: list[CatalogPR] = []
         self._refresh_pr_list()
 
-        def _compute_own_refs(self, explicit_ref: str | None) -> list[str]:
-            """Thin GUI-side wrapper: injects current_branch(self.repo_dir)
-            (a git call) into the pure compute_own_refs() -- see that
-            function's docstring for what this list actually means."""
-            return compute_own_refs(explicit_ref, current_branch(self.repo_dir))
-
     def _refresh_pr_list(self):
         self._prs = list_open_catalog_prs(self._token)
-            while self.source_list.count() > len(self._own_refs):
+        while self.source_list.count() > 1:
-                self.source_list.takeItem(len(self._own_refs))
+            self.source_list.takeItem(1)
         for pr in self._prs:
             self.source_list.addItem(QListWidgetItem(f"PR #{pr.number}: {pr.title}"))
 
-        def _load_own_ref(self, loaded_ref: str):
+    def _on_load(self):
-            """Load + diff `loaded_ref` -- "main" or the maintainer's own
+        row = self.source_list.currentRow()
-            working branch, ANY ref this clone's origin can fetch directly (as
+        try:
-            opposed to a PR's read-only refs/pull/<n>/head). Diffs against the
+            if row <= 0:
-            last catalog a maintainer actually SIGNED on that ref (never
+                # source = main: diff against the last catalog a maintainer
-            against itself -- an empty diff must mean "nothing to sign", never
+                # actually SIGNED (the bytes covered by the current
-            "sign unlocked", issue #68 finding 1) and enters KEY-ROTATION
+                # data/catalog.json.sig), never against itself. Diffing
-            RE-ATTESTATION mode if the committed .sig doesn't verify under the
+                # main-vs-main is what made an empty diff -> instantly
-            currently-trusted bcc_core.CATALOG_PUBKEYS (issue #68 finding 5
+                # "signable" in the first place (issue #68 finding 1) --
-            follow-up). This is the exact logic "main" always used -- pulled
+                # this is the only path that reaches sign_catalog_bytes(),
-            into its own method, parameterized on the ref, so a rotation on a
+                # so if it can't be trusted nothing can.
-            branch gets the SAME treatment as one on main and can be signed
+                loaded_ref = "main"
-            (and pushed back to that SAME branch, see _on_sign) before merge --
-            the completability fix this method exists for.
-
-            Returns (new_raw, new_blob_sha, new_catalog, old_catalog, reattest).
-            """
                 commit = fetch_ref(self.repo_dir, loaded_ref)
                 new_raw, new_blob_sha = read_catalog_at_commit(self.repo_dir, commit)
                 new_catalog = core.load_catalog(new_raw)
-
-            if not catalog_signature_valid_at(self.repo_dir, commit, new_raw):
-                reattest = True
-                old_catalog = dict(self._EMPTY_CATALOG)
-            else:
-                reattest = False
                 old_raw = last_signed_catalog_raw(self.repo_dir, commit)
                 old_catalog = (
-                    core.load_catalog(old_raw) if old_raw is not None else dict(self._EMPTY_CATALOG)
+                    core.load_catalog(old_raw)
-                )
+                    if old_raw is not None
-
+                    else {
-            return new_raw, new_blob_sha, new_catalog, old_catalog, reattest
+                        "schema": 1,
-
+                        "version": 0,
-        def _on_load(self):
+                        "servers": [],
-            row = self.source_list.currentRow()
+                    }
-            if row < 0:
-                row = 0  # nothing explicitly selected -- default to index 0 ("main")
-            try:
-                if row < len(self._own_refs):
-                    loaded_ref = self._own_refs[row]
-                    new_raw, new_blob_sha, new_catalog, old_catalog, reattest = self._load_own_ref(
-                        loaded_ref
                 )
             else:
-                    pr = self._prs[row - len(self._own_refs)]
+                pr = self._prs[row - 1]
                 loaded_ref = pr.head_ref
-                    reattest = False
                 commit = fetch_ref(self.repo_dir, loaded_ref)
                 old_commit = fetch_ref(self.repo_dir, "main")
 
@@ -1081,21 +781,8 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
         # from the SAME ref that was reviewed, instead of a hardcoded
         # "main" -- see review.sign_precondition and issue #68 finding 1.
         self.session = review.start_review(
-                new_blob_sha, old_catalog, new_catalog, loaded_ref=loaded_ref, reattest=reattest
+            new_blob_sha, old_catalog, new_catalog, loaded_ref=loaded_ref
         )
-            if reattest:
-                self.reattest_banner.setText(
-                    "KEY ROTATION IN PROGRESS -- the trusted CATALOG signing key changed. "
-                    "The existing data/catalog.json.sig does NOT verify under the current "
-                    "bcc_core.CATALOG_PUBKEYS, so it is NOT trusted. Every one of the "
-                    f"{len(self.session.changes)} entries below must be re-reviewed and "
-                    "acknowledged before the new CATALOG key can re-sign this catalog -- "
-                    "this is the intended cost of rotating the CATALOG key, not a bug."
-                )
-                self.reattest_banner.setVisible(True)
-            else:
-                self.reattest_banner.setVisible(False)
-                self.reattest_banner.setText("")
         self._render_cards()
 
     def _render_cards(self):
@@ -1107,11 +794,7 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
 
         assert self.session is not None
         all_ids = sorted(
-                {
+            {e.get("id") for e in (self.session.new_catalog.get("servers") or []) if e.get("id")}
-                    e.get("id")
-                    for e in (self.session.new_catalog.get("servers") or [])
-                    if e.get("id")
-                }
         )
         for change in self.session.changes:
             card = EntryCard(change, all_ids)
@@ -1134,12 +817,6 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
         all_ack = review.all_entries_acknowledged(self.session)
         self.sign_btn.setEnabled(all_ack)
         pending = len(self.session.changes) - len(self.session.acknowledged)
-            if self.session.reattest:
-                self.status_label.setText(
-                    f"RE-ATTESTATION under the new key: {len(self.session.changes)} entries, "
-                    f"{pending} not yet acknowledged."
-                )
-            else:
         self.status_label.setText(
             f"{len(self.session.changes)} changed entries, {pending} not yet acknowledged."
         )
@@ -1182,52 +859,23 @@ if _PYSIDE6_AVAILABLE:  # pragma: no branch - GUI class defs, only skipped where
                 self._on_load()
             return
 
-            # Show WHICH key is about to be used, and its fingerprint, BEFORE
+        dialog = PassphraseDialog("Enter CATALOG signing key passphrase:", self)
-            # the passphrase field even appears -- issue #62/#68 follow-up. A
-            # maintainer must never have to infer which key a bare "Enter
-            # passphrase" prompt means; that ambiguity is exactly what led to a
-            # private key being pasted into a chat window.
-            catalog_pubkey = load_public_key("catalog")
-            if catalog_pubkey is not None:
-                fp_note = f"fingerprint {review.fingerprint_pubkey(catalog_pubkey)}"
-            else:
-                fp_note = "fingerprint unknown (generated before fingerprint caching -- re-run keygen to cache it)"
-            prompt = (
-                f"About to sign with the CATALOG signing key ({fp_note}).\n"
-                "This is the root of trust for what BCC executes on a user's machine -- "
-                "it is never the RELEASE key.\n\n"
-                "Enter the CATALOG key's passphrase:"
-            )
-            dialog = PassphraseDialog(prompt, "CATALOG signing key passphrase", self)
         if dialog.exec() != QDialog.DialogCode.Accepted:
             return
         try:
-                seed = unlock_signing_key(dialog.passphrase(), kind="catalog")
+            seed = unlock_signing_key(dialog.passphrase())
         except (FileNotFoundError, ValueError) as e:
             QMessageBox.critical(self, "Sign failed", html.escape(str(e)))
             return
 
         signature = review.sign_catalog_bytes(self._new_raw, seed)
         try:
-                # Push to the SAME ref that was reviewed (session.loaded_ref),
+            new_commit = commit_and_push_signed_catalog(self.repo_dir, self._new_raw, signature)
-                # never a hardcoded "main" -- issue #68 completability fix. A
-                # rotation (or any other catalog change) reviewed on a branch
-                # must land on THAT branch so it can be signed and pushed
-                # before the branch is ever merged, instead of forcing a merge
-                # of a red PR followed by a fix-up on main.
-                new_commit = commit_and_push_signed_catalog(
-                    self.repo_dir, self._new_raw, signature, branch=self.session.loaded_ref
-                )
         except GitError as e:
             QMessageBox.critical(self, "Commit/push failed", html.escape(str(e)))
             return
 
-            QMessageBox.information(
+        QMessageBox.information(self, "Signed", f"Signed and pushed as commit {new_commit[:12]}.")
-                self,
-                "Signed",
-                f"Signed with the CATALOG key and pushed to {self.session.loaded_ref} "
-                f"as commit {new_commit[:12]}.",
-            )
         self.sign_btn.setEnabled(False)
 
 
@@ -1257,10 +905,9 @@ def cmd_keygen(args: argparse.Namespace) -> int:
 
     blob = review.encrypt_private_key(seed, passphrase)
     where = store_encrypted_key(blob, kind=kind)
-    store_public_key(pubkey, kind=kind)  # non-secret; lets `keys` fingerprint without a passphrase
     pubkey_b64 = base64.b64encode(pubkey).decode("ascii")
 
-    print(f"{kind.upper()} private key encrypted and stored in: {where}")
+    print(f"{kind.capitalize()} private key encrypted and stored in: {where}")
     print()
     if kind == "catalog":
         print(
@@ -1273,12 +920,8 @@ def cmd_keygen(args: argparse.Namespace) -> int:
         )
         print()
         print(
-            "PUBLIC key (base64, safe to commit/share) -- hand this to whoever "
+            "Public key (base64) -- hand this to whoever maintains bcc_core.py so "
-            "maintains bcc_core.py so they can add it to CATALOG_PUBKEYS (this tool "
+            "they can add it to CATALOG_PUBKEYS (this tool does not edit that file):"
-            "does not edit that file). There is no PRIVATE-key output for the catalog "
-            "key: it is never meant to leave this machine, and this tool has no "
-            "command that exports it (show-seed-b64 refuses without --release, and "
-            "even then only exports the release key)."
         )
         print(f"    {pubkey_b64}")
     else:
@@ -1289,23 +932,14 @@ def cmd_keygen(args: argparse.Namespace) -> int:
             "contain it)."
         )
         print()
-        print(
+        print("1. Public key (base64) -- paste into scripts/sign_checksums.py RELEASE_PUBKEYS:")
-            "1. PUBLIC key (base64, safe to commit/share) -- paste into "
-            "scripts/sign_checksums.py RELEASE_PUBKEYS:"
-        )
         print(f"    {pubkey_b64}")
         print()
         print(
-            "2. PRIVATE key (secret -- NEVER commit, NEVER paste into chat/email) -- "
+            "2. Private key -- add it as the Gitea repo secret RELEASE_SIGNING_KEY "
-            "add it as the Gitea repo secret RELEASE_SIGNING_KEY (base64 of the "
+            "(base64 of the 32-byte private seed). Get that value with:"
-            "32-byte private seed). This command does not print it; fetch it "
-            "separately, when you're ready to paste it straight into the Gitea "
-            "secret field, with:"
-        )
-        print(
-            "    python catalog_console.py show-seed-b64 --release   "
-            "# prints the PRIVATE key -- read the warning banner it shows"
         )
+        print("    python catalog_console.py show-seed-b64 --release   # prints the raw key")
     return 0
 
 
@@ -1325,49 +959,17 @@ def cmd_show_seed_b64(args: argparse.Namespace) -> int:
             file=sys.stderr,
         )
         return 1
-    # The prior wording ("Release signing key passphrase:") was ambiguous
+    passphrase = getpass.getpass("Release signing key passphrase: ")
-    # enough that a maintainer who ran this command, saw that prompt, and
-    # then saw a base64 blob printed with zero surrounding context, pasted
-    # the output into a chat believing it was the PUBLIC key. It is not --
-    # it is the raw private seed. Every string this command prints from here
-    # down exists to make that mistake structurally harder to make again.
-    passphrase = getpass.getpass(
-        "Passphrase for the release signing key (the one YOU chose when generating it): "
-    )
     try:
         seed = unlock_signing_key(passphrase, kind="release")
     except (FileNotFoundError, ValueError) as e:
         print(f"error: {e}", file=sys.stderr)
         return 1
-
-    # Loud banner on STDERR, seed alone on STDOUT -- so `show-seed-b64
-    # --release | pbcopy` (or piping into the Gitea secret field) still
-    # gets ONLY the seed, while anyone watching the terminal still sees the
-    # warning. Never merge these into one stream.
-    print("!!! PRIVATE KEY BELOW -- this is the RELEASE_SIGNING_KEY secret value.", file=sys.stderr)
-    print(
-        "!!! Paste it ONLY into the Gitea secret field. Never into chat, email, "
-        "a file, or a commit.",
-        file=sys.stderr,
-    )
-    print(
-        "!!! Anyone holding this value can forge release checksum signatures.",
-        file=sys.stderr,
-    )
     print(base64.b64encode(seed).decode("ascii"))
     return 0
 
 
 def cmd_gui(args: argparse.Namespace) -> int:
-    if not _PYSIDE6_AVAILABLE:
-        print(
-            "error: PySide6 is not available in this Python environment, so the GUI "
-            f"can't launch ({_PYSIDE6_IMPORT_ERROR}). `keygen`, `show-seed-b64`, and "
-            "`keys` don't need it and still work here.",
-            file=sys.stderr,
-        )
-        return 1
-
     repo_dir = Path(args.repo).resolve()
     if not (repo_dir / CATALOG_PATH).exists():
         print(
@@ -1378,98 +980,18 @@ def cmd_gui(args: argparse.Namespace) -> int:
 
     app = QApplication(sys.argv)
     app.setApplicationName("BCC Catalog Console")
-    win = ReviewWindow(repo_dir, ref=args.ref)
+    win = ReviewWindow(repo_dir)
     win.resize(900, 700)
     win.show()
     return app.exec()
 
 
-def cmd_keys(args: argparse.Namespace) -> int:
-    """`python catalog_console.py keys` -- "which key is what, and what
-    state is everything in?" (issue #62/#68 follow-up). Reads the CURRENT
-    WORKING TREE at --repo (so it reports on whatever branch/ref is
-    actually checked out there -- issue #68 rotation-completability fix
-    means that's often not "main" during a rotation), gathers every input
-    the pure catalog_review.key_status()/render_key_status_report() need,
-    and prints the result. Never touches, decrypts, or prints a private key
-    -- everything gathered here is a cached PUBLIC key, a fingerprint, file
-    text, or a signature verification result.
-    """
-    repo_dir = Path(args.repo).resolve()
-    branch = current_branch(repo_dir) or "(unknown -- detached HEAD or not a git checkout)"
-    print(f"Catalog Console -- key status for {repo_dir}")
-    print(f"Checked-out ref: {branch}")
-    print()
-
-    committed_catalog_pubkeys = read_catalog_pubkeys_from_source(repo_dir)
-    ci_trust_anchor_pubkeys = read_ci_trust_anchor_pubkeys(repo_dir)
-    committed_release_pubkeys = read_release_pubkeys_from_source(repo_dir)
-
-    catalog_status = review.key_status(
-        "catalog",
-        display_name="CATALOG",
-        purpose=(
-            "Signs the server list that BCC writes into your Claude config. This is "
-            "what decides which programs run on a user's machine -- the root of trust."
-        ),
-        private_key_location=describe_local_key_location("catalog"),
-        local_exists=has_encrypted_key("catalog"),
-        local_pubkey=load_public_key("catalog"),
-        locations=[
-            ("bcc_core.CATALOG_PUBKEYS", committed_catalog_pubkeys),
-            ("ci.yml trust anchor (EXPECTED_CATALOG_PUBKEY_B64)", ci_trust_anchor_pubkeys),
-        ],
-        catalog_sig_status=catalog_sig_status_on_disk(repo_dir, committed_catalog_pubkeys),
-    )
-
-    release_where = describe_local_key_location("release")
-    if release_where == "not generated yet":
-        release_where = (
-            "not generated yet, and not verifiable from here as present in CI "
-            "(check the Gitea repo secret RELEASE_SIGNING_KEY directly)"
-        )
-    else:
-        release_where = (
-            f"{release_where} -- intended to be pasted into the Gitea secret "
-            "RELEASE_SIGNING_KEY (via `show-seed-b64 --release`) and not kept as the "
-            "primary copy once that's done"
-        )
-    release_status = review.key_status(
-        "release",
-        display_name="RELEASE",
-        purpose=(
-            "Signs the SHA256SUMS checksum manifest for release downloads only. "
-            "CI-resident on purpose: a CI compromise burns this key, never the "
-            "catalog key -- that asymmetry is the whole point of having two keys."
-        ),
-        private_key_location=release_where,
-        local_exists=has_encrypted_key("release"),
-        local_pubkey=load_public_key("release"),
-        locations=[("scripts/sign_checksums.py RELEASE_PUBKEYS", committed_release_pubkeys)],
-        catalog_sig_status=None,
-    )
-
-    print(review.render_key_status_report([catalog_status, release_status]))
-    return 0
-
-
 def build_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(description=__doc__)
     sub = parser.add_subparsers(dest="command")
 
     p_gui = sub.add_parser("gui", help="launch the review/sign GUI (default)")
     p_gui.add_argument("--repo", default=".", help="path to a BCC git checkout (default: cwd)")
-    p_gui.add_argument(
-        "--ref",
-        default=None,
-        help=(
-            "branch to offer as an additional load/sign/push source, alongside "
-            "'main' and any open PRs -- e.g. a key-rotation branch, so rotation "
-            "can be reviewed and signed BEFORE merge instead of forcing a red main "
-            "(issue #68). Defaults to whatever branch --repo is currently checked "
-            "out on; only needed if that's not the branch you mean."
-        ),
-    )
     p_gui.set_defaults(func=cmd_gui)
 
     p_keygen = sub.add_parser(
@@ -1497,21 +1019,10 @@ def build_parser() -> argparse.ArgumentParser:
     )
     p_seed.set_defaults(func=cmd_show_seed_b64)
 
-    p_keys = sub.add_parser(
-        "keys",
-        help=(
-            "print a plain-English status report: which key is what, where its "
-            "private half lives, whether it matches what's committed, and whether "
-            "data/catalog.json.sig currently verifies"
-        ),
-    )
-    p_keys.add_argument("--repo", default=".", help="path to a BCC git checkout (default: cwd)")
-    p_keys.set_defaults(func=cmd_keys)
-
     return parser
 
 
-_SUBCOMMANDS = ("gui", "keygen", "show-seed-b64", "keys", "-h", "--help")
+_SUBCOMMANDS = ("gui", "keygen", "show-seed-b64", "-h", "--help")
 
 
 def main(argv: list[str] | None = None) -> int:

catalog_review.py

@@ -16,8 +16,6 @@ new surface" recurring-bug lesson).
 
 from __future__ import annotations
 
-import base64
-import hashlib
 import os
 import re
 from collections.abc import Callable
@@ -444,42 +442,17 @@ class ReviewSession:
     from the reviewed ref on every PR review (the bug that made the PR path
     unable to sign at all, and forced everyone onto the vacuous
     main-vs-itself path instead).
-
-    `reattest` marks a KEY-ROTATION re-attestation pass (issue #68 finding 5
-    follow-up): the currently-trusted `bcc_core.CATALOG_PUBKEYS` key changed
-    and the existing `data/catalog.json.sig` no longer verifies under it.
-    Content-wise nothing may have changed -- `diff_catalogs(old, new)` can be
-    genuinely empty -- but the NEW key has never vouched for any of this
-    catalog before, so every entry needs a first-time attestation under the
-    new key, not a diff against the old one. When `reattest` is set,
-    `changes` is built as "every entry in `new_catalog`, presented as if
-    newly added" (via `diff_catalogs(None, new_catalog)`) instead of a
-    diff against `old_catalog`, so the acknowledge-gate in `can_sign()`
-    requires re-reviewing everything the new key will sign -- which is the
-    intended cost of a key rotation, not a bypass of the empty-diff guard.
     """
 
     pinned_blob_sha: str
     old_catalog: dict
     new_catalog: dict
     loaded_ref: str = "main"
-    reattest: bool = False
     changes: list[EntryChange] = field(default_factory=list)
     acknowledged: set[str] = field(default_factory=set)
 
     def __post_init__(self) -> None:
         if not self.changes:
-            if self.reattest:
-                # Every entry in the new catalog is treated as though it
-                # were newly added -- because, under the NEW signing key,
-                # it is: nothing this key signs was ever attested by it
-                # before. Reusing diff_catalogs(None, new) (rather than a
-                # bespoke code path) means the same "added" risk predicate
-                # (risk_new_entry) and the same EntryChange shape the rest
-                # of this module and the GUI already know how to render
-                # apply here unmodified.
-                self.changes = diff_catalogs(None, self.new_catalog)
-            else:
             self.changes = diff_catalogs(self.old_catalog, self.new_catalog)
 
 
@@ -488,14 +461,12 @@ def start_review(
     old_catalog: dict,
     new_catalog: dict,
     loaded_ref: str = "main",
-    reattest: bool = False,
 ) -> ReviewSession:
     return ReviewSession(
         pinned_blob_sha=pinned_blob_sha,
         old_catalog=old_catalog,
         new_catalog=new_catalog,
         loaded_ref=loaded_ref,
-        reattest=reattest,
     )
 
 
@@ -560,14 +531,6 @@ def can_sign(session: ReviewSession, current_blob_sha: str) -> SignDecision:
        mean "nothing to sign", never "sign unlocked". (Issue #68 finding 1;
        this is what let commit b08cf21 sign all 19 entries with zero of them
        ever reviewed.)
-
-       This gate is unaffected by `session.reattest`: a key-rotation
-       re-attestation session's `changes` is built from
-       `diff_catalogs(None, new_catalog)` (see ReviewSession), which is
-       empty ONLY if the catalog itself has zero entries -- a genuinely
-       empty catalog either way. Rotation never manufactures a non-empty
-       changeset out of an empty one; it just changes *what* "non-empty"
-       is computed against.
     1. TOCTOU: `current_blob_sha` (fetched fresh, immediately before signing,
        from the ref that was actually reviewed -- see sign_precondition())
        must match the blob SHA pinned when review began. If the bytes on the
@@ -853,243 +816,3 @@ _NON_ASCII_RE = re.compile(r"[^\x00-\x7f]")
 
 def contains_non_ascii(s: str) -> bool:
     return bool(_NON_ASCII_RE.search(s))
-
-
-# --------------------------------------------------------------------------- #
-# Key status reporting (issue #62/#68 follow-up: "make key handling
-# comprehensible"). Pure functions only -- `catalog_console.py cmd_keys` is a
-# thin printer that gathers inputs (local key caches, source-file text, the
-# catalog + its .sig) and hands them here. NEVER touches private key bytes:
-# every input/output here is a public key, a fingerprint, or a status string.
-# --------------------------------------------------------------------------- #
-
-
-def fingerprint_pubkey(pubkey: bytes) -> str:
-    """Short, human-comparable fingerprint of a raw Ed25519 public key: the
-    first 16 hex chars of its SHA-256 digest, grouped in 4s (e.g. "3F2A 9C1B
-    44DE 08AA") so two fingerprints can be eyeballed for a mismatch the way a
-    PGP fingerprint is. Deliberately NOT the raw base64 pubkey itself in the
-    default short form (that's available via the full committed value in the
-    report) -- a fixed-width grouped hex string is easier to compare at a
-    glance and to read aloud/type over chat if needed. Never derived from,
-    and never printed alongside, any private key material.
-    """
-    digest = hashlib.sha256(pubkey).hexdigest().upper()[:16]
-    return " ".join(digest[i : i + 4] for i in range(0, len(digest), 4))
-
-
-_PUBKEY_LIST_B64_RE = re.compile(r'base64\.b64decode\(\s*"([^"]+)"\s*\)')
-
-
-def extract_pubkey_list_literal(source_text: str, var_name: str) -> list[bytes]:
-    """Best-effort extraction of a `<var_name>: list[bytes] = [...]` literal
-    (each entry a `base64.b64decode("...")` call, matching the exact style
-    bcc_core.CATALOG_PUBKEYS and scripts.sign_checksums.RELEASE_PUBKEYS are
-    both written in) straight out of Python source TEXT.
-
-    Deliberately a regex over text, not an import: `catalog_console.py keys`
-    must report on whatever ref/branch is checked out at the inspected repo
-    path, which may not be (and need not be) importable from the running
-    process's own sys.path. Returns [] if the variable isn't found in this
-    exact shape -- callers treat that as "nothing committed here", not an
-    error, since a report that can't parse a file should say so plainly
-    rather than crash the whole `keys` command over one malformed file.
-    """
-    match = re.search(
-        rf"{re.escape(var_name)}\s*:\s*list\[bytes\]\s*=\s*\[(.*?)\]", source_text, re.DOTALL
-    )
-    if not match:
-        return []
-    keys: list[bytes] = []
-    for b64 in _PUBKEY_LIST_B64_RE.findall(match.group(1)):
-        try:
-            keys.append(base64.b64decode(b64))
-        except ValueError:
-            continue
-    return keys
-
-
-_CI_TRUST_ANCHOR_RE = re.compile(r'EXPECTED_CATALOG_PUBKEY_B64:\s*"([^"]+)"')
-
-
-def extract_ci_trust_anchor_pubkey(ci_yml_text: str) -> bytes | None:
-    """Best-effort extraction of ci.yml's `EXPECTED_CATALOG_PUBKEY_B64` trust
-    anchor (issue #68 finding 4) from the workflow file's TEXT. Returns None
-    if the constant isn't found -- the `keys` report shows that plainly
-    ("not found in ci.yml") rather than raising.
-    """
-    match = _CI_TRUST_ANCHOR_RE.search(ci_yml_text)
-    if not match:
-        return None
-    try:
-        return base64.b64decode(match.group(1))
-    except ValueError:
-        return None
-
-
-@dataclass(frozen=True)
-class PubkeyLocationCheck:
-    """One place in the source tree a key's public half is expected to be
-    committed, and whether the fingerprint(s) found there match the key
-    stored locally."""
-
-    location: str
-    committed_fingerprints: tuple[str, ...]
-    status: str  # "match" | "mismatch" | "unknown" (no local key to compare against)
-
-
-@dataclass(frozen=True)
-class KeyStatus:
-    """Everything `catalog_console.py keys` reports about ONE signing key.
-    Built by key_status() below; rendered by render_key_status_report().
-    Never carries private key material -- every field here is safe to print.
-    """
-
-    kind: str  # "catalog" | "release"
-    display_name: str  # "CATALOG" | "RELEASE"
-    purpose: str  # one-line plain-English purpose
-    private_key_location: str  # human-readable, e.g. "on this machine, in the OS keychain"
-    local_exists: bool
-    local_fingerprint: str | None
-    locations: tuple[PubkeyLocationCheck, ...]
-    catalog_sig_status: str | None = None  # "valid" | "invalid" | "missing" | None (n/a)
-
-
-def key_status(
-    kind: str,
-    *,
-    display_name: str,
-    purpose: str,
-    private_key_location: str,
-    local_exists: bool,
-    local_pubkey: bytes | None,
-    locations: list[tuple[str, list[bytes]]],
-    catalog_sig_status: str | None = None,
-) -> KeyStatus:
-    """Pure assembly of a KeyStatus from already-resolved inputs (no file or
-    git I/O here -- that's catalog_console.py's job). `locations` is a list
-    of (label, committed_pubkeys) pairs, e.g.
-    [("bcc_core.CATALOG_PUBKEYS", [...]), ("ci.yml trust anchor", [...])],
-    so a key can be checked against every place its public half is expected
-    to be committed, independently -- this is the check that would have
-    caught bcc_core.CATALOG_PUBKEYS and ci.yml's trust anchor silently
-    drifting apart (issue #68 finding 4 was exactly that kind of drift).
-    """
-    checks: list[PubkeyLocationCheck] = []
-    for label, committed_pubkeys in locations:
-        fps = tuple(fingerprint_pubkey(pk) for pk in committed_pubkeys)
-        if local_pubkey is None:
-            status = "unknown"
-        elif local_pubkey in committed_pubkeys:
-            status = "match"
-        else:
-            status = "mismatch"
-        checks.append(
-            PubkeyLocationCheck(location=label, committed_fingerprints=fps, status=status)
-        )
-
-    return KeyStatus(
-        kind=kind,
-        display_name=display_name,
-        purpose=purpose,
-        private_key_location=private_key_location,
-        local_exists=local_exists,
-        local_fingerprint=fingerprint_pubkey(local_pubkey) if local_pubkey is not None else None,
-        locations=tuple(checks),
-        catalog_sig_status=catalog_sig_status,
-    )
-
-
-_LOCATION_STATUS_ICON = {"match": "✅", "mismatch": "❌", "unknown": "⚠️"}
-_LOCATION_STATUS_VERDICT = {
-    "match": "MATCHES the local private key",
-    "mismatch": "DOES NOT MATCH the local private key",
-    "unknown": "cannot compare -- no local key to check against",
-}
-_CATALOG_SIG_STATUS_LINE = {
-    "valid": "✅ data/catalog.json.sig verifies under the committed CATALOG_PUBKEYS.",
-    "invalid": (
-        "❌ data/catalog.json.sig does NOT verify under the committed CATALOG_PUBKEYS -- "
-        "the catalog needs re-signing (Load → acknowledge all → Sign)."
-    ),
-    "missing": (
-        "⚠️ data/catalog.json.sig is missing entirely -- the catalog has never been signed."
-    ),
-}
-
-
-def recommend_next_steps(statuses: list[KeyStatus]) -> list[str]:
-    """The pure "what to do next" logic behind the keys report's closing
-    section -- one concrete, runnable-looking instruction per problem found,
-    naming the exact key involved (never just "the key"). Returns a single
-    reassuring line if nothing needs attention."""
-    steps: list[str] = []
-    for s in statuses:
-        if not s.local_exists:
-            flag = " --release" if s.kind == "release" else ""
-            steps.append(
-                f"{s.display_name} key has never been generated on this machine -- run "
-                f"`python catalog_console.py keygen{flag}`."
-            )
-            continue
-        for loc in s.locations:
-            if loc.status == "mismatch":
-                steps.append(
-                    f"{s.display_name} key's local fingerprint does not match "
-                    f"{loc.location} -- update {loc.location} to the fingerprint shown "
-                    "above (or, if this is unexpected, treat the committed key as "
-                    "untrusted and investigate before doing anything else)."
-                )
-            elif loc.status == "unknown":
-                steps.append(
-                    f"{s.display_name} key's local fingerprint could not be checked against "
-                    f"{loc.location} -- re-run keygen (or, for an older install, unlock the "
-                    "key once) so its public half is cached locally."
-                )
-        if s.kind == "catalog" and s.catalog_sig_status in ("invalid", "missing"):
-            steps.append(
-                "The catalog needs re-signing: run `python catalog_console.py gui --repo .` "
-                "and Load → acknowledge every entry → Sign. If main is red because "
-                "of a key rotation, load the branch with the rotation instead of main "
-                "(current-branch / --ref source) so the fix lands before merge."
-            )
-    if not steps:
-        steps.append("Everything is consistent -- no action needed.")
-    return steps
-
-
-def render_key_status_report(statuses: list[KeyStatus]) -> str:
-    """Render a full, plain-English-first key status report as one string.
-    `catalog_console.py cmd_keys` prints this verbatim -- the CLI is a thin
-    printer over this pure function, which is what makes the report's
-    content (not just its plumbing) unit-testable."""
-    lines: list[str] = []
-    for s in statuses:
-        lines.append(f"=== {s.display_name} KEY ===")
-        lines.append(s.purpose)
-        lines.append(f"Private half lives: {s.private_key_location}")
-        if s.local_exists and s.local_fingerprint:
-            lines.append(f"Exists locally: yes (fingerprint {s.local_fingerprint})")
-        elif s.local_exists:
-            lines.append("Exists locally: yes (fingerprint unknown -- re-run keygen to cache it)")
-        else:
-            lines.append("Exists locally: no")
-        for loc in s.locations:
-            icon = _LOCATION_STATUS_ICON.get(loc.status, "?")
-            fps = (
-                ", ".join(loc.committed_fingerprints)
-                if loc.committed_fingerprints
-                else "(nothing committed here)"
-            )
-            verdict = _LOCATION_STATUS_VERDICT.get(loc.status, loc.status)
-            lines.append(f"  {icon} {loc.location}: {fps} -- {verdict}")
-        if s.catalog_sig_status is not None:
-            lines.append(
-                f"Catalog signature: {_CATALOG_SIG_STATUS_LINE.get(s.catalog_sig_status, s.catalog_sig_status)}"
-            )
-        lines.append("")
-
-    lines.append("What to do next:")
-    for step in recommend_next_steps(statuses):
-        lines.append(f"  - {step}")
-    return "\n".join(lines)

scripts/sign_checksums.py

@@ -53,17 +53,13 @@ DOMAIN_PREFIX = b"bcc-release-v1|"
 # the signature on every past release: verification accepts a match against
 # ANY key here.
 #
-# Populated by the maintainer via:
+# Empty until the maintainer generates the release keypair (separately from
+# the catalog keypair) and pastes the public half in:
 #     python catalog_console.py keygen --release
-# Rotated 2026-07 (issue #68 finding 5 / #68 CI-exposure incident): the
+# This is intentionally NOT pre-populated with a placeholder that looks
-# original key was shared with the catalog key and had been exposed to CI,
+# like a real key -- release.yml's signing-smoke-test fails closed (loudly)
-# so both keypairs were regenerated as separate, disjoint keys. This list
+# on an empty list rather than silently verifying against nothing.
-# holds only the current release key -- if release.yml's signing-smoke-test
+RELEASE_PUBKEYS: list[bytes] = []
-# ever sees this list empty, it fails closed (loudly) rather than silently
-# verifying against nothing.
-RELEASE_PUBKEYS: list[bytes] = [
-    base64.b64decode("6BnPgJEHJFyVltFoLTCNadIsehjy00iiW8IRlC1TfhA="),
-]
 
 CHUNK_SIZE = 1024 * 1024
 

tests/test_catalog_console_git.py

@@ -1,215 +0,0 @@
-"""Tests for catalog_console.py's non-Qt git plumbing and ref-resolution
-seam (issue #68 rotation-completability fix).
-
-catalog_console.py is importable here WITHOUT PySide6 -- its Qt import is
-guarded (`_PYSIDE6_AVAILABLE`) precisely so `keygen`, `show-seed-b64`,
-`keys`, and this git plumbing stay usable (and testable) wherever PySide6
-isn't installed, including this CI test job, which never installs it. If
-PySide6 genuinely isn't importable in this environment, that itself
-exercises the guard path -- see test_module_imports_without_pyside6.
-"""
-
-from __future__ import annotations
-
-import subprocess
-import sys
-from pathlib import Path
-
-sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
-
-import catalog_console as cc
-import catalog_review as review
-
-_SEED_CATALOG = b'{"schema": 1, "version": 1, "servers": []}'
-_SEED_SIG = b"\x00" * 64
-
-
-def _run(*args: str, cwd: Path) -> None:
-    subprocess.run(["git", *args], cwd=cwd, check=True, capture_output=True)
-
-
-def _init_bare_and_clone(tmp_path: Path) -> tuple[Path, Path]:
-    """A bare "origin" repo with `main` and `rotation-branch` both seeded
-    with a catalog + (dummy) signature, plus a working clone with `origin`
-    already configured -- mirroring the tokened-remote clone
-    catalog_console.py's git plumbing is always run against."""
-    origin = tmp_path / "origin.git"
-    _run("init", "--bare", str(origin), cwd=tmp_path)
-
-    seed = tmp_path / "seed"
-    _run("clone", str(origin), str(seed), cwd=tmp_path)
-    _run("config", "user.email", "test@example.com", cwd=seed)
-    _run("config", "user.name", "Test", cwd=seed)
-
-    (seed / "data").mkdir()
-    (seed / "data" / "catalog.json").write_bytes(_SEED_CATALOG)
-    (seed / "data" / "catalog.json.sig").write_bytes(_SEED_SIG)
-    _run("add", "-A", cwd=seed)
-    _run("commit", "-m", "seed", cwd=seed)
-    _run("push", "origin", "HEAD:refs/heads/main", cwd=seed)
-    _run("checkout", "-b", "rotation-branch", cwd=seed)
-    _run("push", "origin", "HEAD:refs/heads/rotation-branch", cwd=seed)
-
-    clone = tmp_path / "work"
-    _run("clone", str(origin), str(clone), cwd=tmp_path)
-    _run("config", "user.email", "test@example.com", cwd=clone)
-    _run("config", "user.name", "Test", cwd=clone)
-    return origin, clone
-
-
-# --------------------------------------------------------------------------- #
-# The module must stay importable without PySide6 -- this IS the fix that
-# lets `keys`/`keygen`/`show-seed-b64` (and this whole test file) run
-# somewhere PySide6 isn't installed.
-# --------------------------------------------------------------------------- #
-def test_module_imports_without_pyside6():
-    assert hasattr(cc, "_PYSIDE6_AVAILABLE")
-    # This CI test job never installs PySide6 (see .github/workflows/ci.yml
-    # "Install test dependencies": pytest + cryptography only) -- so on CI,
-    # this assertion is itself proof the guard is doing its job. Locally,
-    # where a maintainer's env DOES have PySide6, it's fine either way; the
-    # only real assertion this test needs is "importing the module never
-    # raises", which happened just by getting this far.
-    assert cc._PYSIDE6_AVAILABLE in (True, False)
-
-
-def test_cmd_gui_fails_soft_without_pyside6(monkeypatch, capsys):
-    if cc._PYSIDE6_AVAILABLE:
-        return  # nothing to prove where PySide6 IS available
-    import argparse
-
-    args = argparse.Namespace(repo=".", ref=None)
-    assert cc.cmd_gui(args) == 1
-    assert "PySide6" in capsys.readouterr().err
-
-
-# --------------------------------------------------------------------------- #
-# compute_own_refs: the PURE ref-resolution seam. No git, no Qt.
-# --------------------------------------------------------------------------- #
-def test_compute_own_refs_defaults_to_main_only():
-    assert cc.compute_own_refs(None, None) == ["main"]
-
-
-def test_compute_own_refs_adds_detected_branch():
-    assert cc.compute_own_refs(None, "chore/68-key-rotation") == [
-        "main",
-        "chore/68-key-rotation",
-    ]
-
-
-def test_compute_own_refs_explicit_ref_overrides_detected_branch():
-    assert cc.compute_own_refs("explicit-branch", "detected-branch") == [
-        "main",
-        "explicit-branch",
-    ]
-
-
-def test_compute_own_refs_does_not_duplicate_main():
-    assert cc.compute_own_refs(None, "main") == ["main"]
-    assert cc.compute_own_refs("main", "some-other-branch") == ["main"]
-
-
-# --------------------------------------------------------------------------- #
-# current_branch: git plumbing, no Qt.
-# --------------------------------------------------------------------------- #
-def test_current_branch_detects_checked_out_branch(tmp_path):
-    _origin, clone = _init_bare_and_clone(tmp_path)
-    _run("fetch", "origin", "rotation-branch", cwd=clone)
-    _run("checkout", "-B", "rotation-branch", "origin/rotation-branch", cwd=clone)
-    assert cc.current_branch(clone) == "rotation-branch"
-
-
-def test_current_branch_none_on_detached_head(tmp_path):
-    _origin, clone = _init_bare_and_clone(tmp_path)
-    commit = cc.fetch_ref(clone, "main")
-    _run("checkout", commit, cwd=clone)
-    assert cc.current_branch(clone) is None
-
-
-# --------------------------------------------------------------------------- #
-# commit_and_push_signed_catalog: MUST target the given branch, never a
-# hardcoded "main" -- issue #68's completability fix. This is exactly the
-# bug that, before the fix, would have made ReviewWindow._on_sign push a
-# PR/branch review's signature straight to main regardless of what was
-# actually reviewed.
-# --------------------------------------------------------------------------- #
-def test_commit_and_push_signed_catalog_targets_the_given_branch_not_main(tmp_path):
-    _origin, clone = _init_bare_and_clone(tmp_path)
-
-    new_raw = b'{"schema": 1, "version": 2, "servers": []}'
-    new_sig = b"\x01" * 64
-    cc.commit_and_push_signed_catalog(clone, new_raw, new_sig, branch="rotation-branch")
-
-    rotation_commit = cc.fetch_ref(clone, "rotation-branch")
-    rotation_raw, _sha = cc.read_catalog_at_commit(clone, rotation_commit)
-    assert rotation_raw == new_raw
-
-    # main on the shared origin must be COMPLETELY untouched by a sign that
-    # was reviewed and pushed against rotation-branch.
-    main_commit = cc.fetch_ref(clone, "main")
-    main_raw, _sha = cc.read_catalog_at_commit(clone, main_commit)
-    assert main_raw == _SEED_CATALOG
-
-
-def test_commit_and_push_signed_catalog_still_defaults_to_main(tmp_path):
-    """Backward-compatible default: callers that don't pass `branch` (there
-    are none left in catalog_console.py itself, but the signature keeps the
-    default for any other caller / test fixture) still push to main."""
-    _origin, clone = _init_bare_and_clone(tmp_path)
-
-    new_raw = b'{"schema": 1, "version": 2, "servers": []}'
-    new_sig = b"\x01" * 64
-    cc.commit_and_push_signed_catalog(clone, new_raw, new_sig)
-
-    main_commit = cc.fetch_ref(clone, "main")
-    main_raw, _sha = cc.read_catalog_at_commit(clone, main_commit)
-    assert main_raw == new_raw
-
-    rotation_commit = cc.fetch_ref(clone, "rotation-branch")
-    rotation_raw, _sha = cc.read_catalog_at_commit(clone, rotation_commit)
-    assert rotation_raw == _SEED_CATALOG  # untouched
-
-
-# --------------------------------------------------------------------------- #
-# catalog_sig_status_on_disk: the check behind `keys`' "does catalog.json.sig
-# currently verify?" line -- this is precisely the check that would have
-# caught the current chore/68-key-rotation state (bcc_core.CATALOG_PUBKEYS
-# rotated, data/catalog.json.sig still signed by the retired key).
-# --------------------------------------------------------------------------- #
-def test_catalog_sig_status_on_disk_valid(tmp_path):
-    seed, pub = review.generate_keypair()
-    raw = b'{"schema": 1, "version": 1, "servers": []}'
-    sig = review.sign_catalog_bytes(raw, seed)
-
-    (tmp_path / "data").mkdir()
-    (tmp_path / "data" / "catalog.json").write_bytes(raw)
-    (tmp_path / "data" / "catalog.json.sig").write_bytes(sig)
-
-    assert cc.catalog_sig_status_on_disk(tmp_path, [pub]) == "valid"
-
-
-def test_catalog_sig_status_on_disk_invalid_when_pubkey_rotated(tmp_path):
-    """The exact chore/68-key-rotation scenario: signed by an OLD key, but
-    the committed pubkey list now only has the NEW key."""
-    old_seed, _old_pub = review.generate_keypair()
-    _new_seed, new_pub = review.generate_keypair()
-    raw = b'{"schema": 1, "version": 1, "servers": []}'
-    sig = review.sign_catalog_bytes(raw, old_seed)
-
-    (tmp_path / "data").mkdir()
-    (tmp_path / "data" / "catalog.json").write_bytes(raw)
-    (tmp_path / "data" / "catalog.json.sig").write_bytes(sig)
-
-    assert cc.catalog_sig_status_on_disk(tmp_path, [new_pub]) == "invalid"
-
-
-def test_catalog_sig_status_on_disk_missing_when_no_sig_file(tmp_path):
-    (tmp_path / "data").mkdir()
-    (tmp_path / "data" / "catalog.json").write_bytes(b"{}")
-    assert cc.catalog_sig_status_on_disk(tmp_path, []) == "missing"
-
-
-def test_catalog_sig_status_on_disk_missing_when_no_catalog_file(tmp_path):
-    (tmp_path / "data").mkdir()
-    (tmp_path / "data" / "catalog.json.sig").write_bytes(b"\x00" * 64)
-    assert cc.catalog_sig_status_on_disk(tmp_path, []) == "missing"

tests/test_catalog_review.py

@@ -491,98 +491,6 @@ def test_sign_precondition_defaults_to_main_when_loaded_ref_unset():
     assert decision.ok is True
 
 
-# --------------------------------------------------------------------------- #
-# ReviewSession(reattest=True): key-rotation re-attestation (issue #68
-# finding 5 follow-up). After rotating bcc_core.CATALOG_PUBKEYS, the
-# existing data/catalog.json.sig no longer verifies under the new key even
-# though catalog CONTENT is unchanged -- diff_catalogs(old, new) would be
-# empty, and an empty changeset must never unlock Sign (can_sign gate 0).
-# Re-attestation mode sidesteps that correctly: instead of diffing against
-# the (now-untrustworthy) last-signed content, it treats every entry as
-# requiring a fresh acknowledgement, exactly like a brand-new catalog.
-# --------------------------------------------------------------------------- #
-def test_reattest_mode_with_unchanged_content_yields_one_change_per_entry():
-    same = _catalog(_entry(id="a"), _entry(id="b"), _entry(id="c"))
-    session = r.start_review("sha1", same, same, reattest=True)
-    assert len(session.changes) == 3
-    assert {c_.entry_id for c_ in session.changes} == {"a", "b", "c"}
-    # Presented "as if newly added" -- old_catalog plays no role here.
-    assert all(c_.status == "added" for c_ in session.changes)
-    assert all(c_.old is None for c_ in session.changes)
-
-
-def test_reattest_mode_can_sign_refuses_until_all_acknowledged_then_permits():
-    same = _catalog(_entry(id="a"), _entry(id="b"), _entry(id="c"))
-    session = r.start_review("sha1", same, same, reattest=True)
-
-    decision = r.can_sign(session, "sha1")
-    assert decision.ok is False
-    assert "acknowledged" in decision.reason.lower()
-
-    r.acknowledge_entry(session, "a")
-    r.acknowledge_entry(session, "b")
-    decision = r.can_sign(session, "sha1")
-    assert decision.ok is False  # "c" still outstanding
-    assert "acknowledged" in decision.reason.lower()
-
-    r.acknowledge_entry(session, "c")
-    decision = r.can_sign(session, "sha1")
-    assert decision.ok is True
-    assert decision.reason is None
-
-
-def test_normal_mode_with_unchanged_content_still_refuses_empty_diff():
-    """The rotation path must NOT become a general bypass of the empty-diff
-    guard: reattest=False (the default) against identical old/new catalogs
-    must behave exactly as before -- can_sign refuses with 'nothing to
-    sign', full stop."""
-    same = _catalog(_entry(id="a"), _entry(id="b"))
-    session = r.start_review("sha1", same, same)  # reattest defaults False
-    assert session.changes == []
-    decision = r.can_sign(session, "sha1")
-    assert decision.ok is False
-    assert "nothing to sign" in decision.reason.lower()
-
-
-def test_reattest_mode_still_enforces_blocking_risk_check():
-    """Re-attestation must not relax the blocking-risk gate: a
-    disallowed-command entry blocks Sign even with every entry
-    acknowledged."""
-    cat = _catalog(
-        _entry(id="a"),
-        _entry(id="evil", config={"command": "bash", "args": ["-c", "rm -rf /"]}),
-    )
-    session = r.start_review("sha1", cat, cat, reattest=True)
-    assert len(session.changes) == 2
-    r.acknowledge_entry(session, "a")
-    r.acknowledge_entry(session, "evil")
-    assert r.all_entries_acknowledged(session) is True
-    decision = r.can_sign(session, "sha1")
-    assert decision.ok is False
-    assert "blocking" in decision.reason.lower()
-
-
-def test_reattest_mode_still_enforces_toctou_pin():
-    """Re-attestation must not relax the TOCTOU blob-SHA pin: acknowledging
-    everything is not enough if the bytes moved underneath the review."""
-    same = _catalog(_entry(id="a"))
-    session = r.start_review("sha1", same, same, reattest=True)
-    r.acknowledge_entry(session, "a")
-    decision = r.can_sign(session, "sha1")
-    assert decision.ok is True  # sanity: matches when blob is unchanged
-
-    decision = r.can_sign(session, "sha2-a-new-commit-landed")
-    assert decision.ok is False
-    assert "mismatch" in decision.reason.lower() or "changed" in decision.reason.lower()
-
-
-def test_reattest_defaults_to_false():
-    """start_review()'s reattest parameter defaults to False -- normal
-    (diff-based) review is the default behaviour, never silently entered."""
-    session = r.start_review("sha1", _catalog(), _catalog(_entry()))
-    assert session.reattest is False
-
-
 # --------------------------------------------------------------------------- #
 # find_last_signed_catalog_raw: what source=main diffs against
 # --------------------------------------------------------------------------- #
@@ -785,245 +693,3 @@ def test_contains_non_ascii_true():
 
 def test_contains_non_ascii_false():
     assert r.contains_non_ascii("package") is False
-
-
-# --------------------------------------------------------------------------- #
-# fingerprint_pubkey
-# --------------------------------------------------------------------------- #
-def test_fingerprint_pubkey_is_deterministic():
-    pub = b"\x01" * 32
-    assert r.fingerprint_pubkey(pub) == r.fingerprint_pubkey(pub)
-
-
-def test_fingerprint_pubkey_differs_for_different_keys():
-    assert r.fingerprint_pubkey(b"\x01" * 32) != r.fingerprint_pubkey(b"\x02" * 32)
-
-
-def test_fingerprint_pubkey_never_contains_the_key_bytes_themselves():
-    pub = b"\x42" * 32
-    fp = r.fingerprint_pubkey(pub)
-    assert pub.hex() not in fp.lower().replace(" ", "")
-
-
-# --------------------------------------------------------------------------- #
-# extract_pubkey_list_literal / extract_ci_trust_anchor_pubkey: text parsing
-# for `catalog_console.py keys`, exercised here with no file I/O.
-# --------------------------------------------------------------------------- #
-def test_extract_pubkey_list_literal_single_key():
-    _seed, pub = r.generate_keypair()
-    import base64
-
-    text = (
-        "CATALOG_PUBKEYS: list[bytes] = [\n"
-        f'    base64.b64decode("{base64.b64encode(pub).decode()}"),\n'
-        "]\n"
-    )
-    assert r.extract_pubkey_list_literal(text, "CATALOG_PUBKEYS") == [pub]
-
-
-def test_extract_pubkey_list_literal_multiple_keys():
-    import base64
-
-    pubs = [r.generate_keypair()[1] for _ in range(2)]
-    body = ",\n".join(f'    base64.b64decode("{base64.b64encode(p).decode()}")' for p in pubs)
-    text = f"RELEASE_PUBKEYS: list[bytes] = [\n{body},\n]\n"
-    assert r.extract_pubkey_list_literal(text, "RELEASE_PUBKEYS") == pubs
-
-
-def test_extract_pubkey_list_literal_missing_variable_returns_empty():
-    assert r.extract_pubkey_list_literal("some unrelated text", "CATALOG_PUBKEYS") == []
-
-
-def test_extract_pubkey_list_literal_does_not_match_a_different_variable():
-    import base64
-
-    _seed, pub = r.generate_keypair()
-    text = f'OTHER_PUBKEYS: list[bytes] = [base64.b64decode("{base64.b64encode(pub).decode()}")]\n'
-    assert r.extract_pubkey_list_literal(text, "CATALOG_PUBKEYS") == []
-
-
-def test_extract_ci_trust_anchor_pubkey_found():
-    import base64
-
-    _seed, pub = r.generate_keypair()
-    text = f'          EXPECTED_CATALOG_PUBKEY_B64: "{base64.b64encode(pub).decode()}"\n'
-    assert r.extract_ci_trust_anchor_pubkey(text) == pub
-
-
-def test_extract_ci_trust_anchor_pubkey_missing_returns_none():
-    assert r.extract_ci_trust_anchor_pubkey("no anchor here") is None
-
-
-# --------------------------------------------------------------------------- #
-# key_status / render_key_status_report / recommend_next_steps
-# --------------------------------------------------------------------------- #
-def _kw(**overrides):
-    base = dict(
-        kind="catalog",
-        display_name="CATALOG",
-        purpose="Signs the catalog.",
-        private_key_location="on this machine",
-        local_exists=True,
-        local_pubkey=b"\x01" * 32,
-        locations=[("bcc_core.CATALOG_PUBKEYS", [b"\x01" * 32])],
-        catalog_sig_status="valid",
-    )
-    base.update(overrides)
-    return base
-
-
-def test_key_status_reports_match_when_local_pubkey_in_committed_list():
-    status = r.key_status(**_kw())
-    assert status.locations[0].status == "match"
-
-
-def test_key_status_reports_mismatch_when_local_pubkey_not_in_committed_list():
-    status = r.key_status(**_kw(locations=[("bcc_core.CATALOG_PUBKEYS", [b"\x02" * 32])]))
-    assert status.locations[0].status == "mismatch"
-
-
-def test_key_status_reports_unknown_when_no_local_pubkey():
-    status = r.key_status(**_kw(local_pubkey=None, local_exists=False))
-    assert status.locations[0].status == "unknown"
-    assert status.local_fingerprint is None
-
-
-def test_key_status_never_carries_a_local_fingerprint_when_key_absent():
-    status = r.key_status(**_kw(local_pubkey=None, local_exists=False))
-    assert status.local_exists is False
-    assert status.local_fingerprint is None
-
-
-def test_key_status_fingerprint_matches_fingerprint_pubkey_helper():
-    pub = b"\x03" * 32
-    status = r.key_status(**_kw(local_pubkey=pub, locations=[("x", [pub])]))
-    assert status.local_fingerprint == r.fingerprint_pubkey(pub)
-
-
-def test_key_status_checks_multiple_locations_independently():
-    """A key can match one committed location and mismatch another -- this
-    is exactly the drift issue #68 finding 4 was about (bcc_core.py and
-    ci.yml silently disagreeing on the trust anchor)."""
-    pub = b"\x04" * 32
-    other = b"\x05" * 32
-    status = r.key_status(
-        **_kw(
-            local_pubkey=pub,
-            locations=[
-                ("bcc_core.CATALOG_PUBKEYS", [pub]),
-                ("ci.yml trust anchor", [other]),
-            ],
-        )
-    )
-    assert status.locations[0].status == "match"
-    assert status.locations[1].status == "mismatch"
-
-
-def test_recommend_next_steps_flags_never_generated_key():
-    status = r.key_status(**_kw(local_exists=False, local_pubkey=None, locations=[]))
-    steps = r.recommend_next_steps([status])
-    assert any("keygen" in s and "CATALOG" in s for s in steps)
-
-
-def test_recommend_next_steps_release_key_uses_release_flag():
-    status = r.key_status(
-        kind="release",
-        display_name="RELEASE",
-        purpose="Signs checksums.",
-        private_key_location="not generated yet",
-        local_exists=False,
-        local_pubkey=None,
-        locations=[],
-    )
-    steps = r.recommend_next_steps([status])
-    assert any("keygen --release" in s for s in steps)
-
-
-def test_recommend_next_steps_flags_mismatch_by_location_name():
-    status = r.key_status(**_kw(locations=[("bcc_core.CATALOG_PUBKEYS", [b"\x99" * 32])]))
-    steps = r.recommend_next_steps([status])
-    assert any("bcc_core.CATALOG_PUBKEYS" in s and "CATALOG" in s for s in steps)
-
-
-def test_recommend_next_steps_flags_invalid_catalog_signature():
-    status = r.key_status(**_kw(catalog_sig_status="invalid"))
-    steps = r.recommend_next_steps([status])
-    assert any("re-signing" in s for s in steps)
-
-
-def test_recommend_next_steps_flags_missing_catalog_signature():
-    status = r.key_status(**_kw(catalog_sig_status="missing"))
-    steps = r.recommend_next_steps([status])
-    assert any("re-signing" in s for s in steps)
-
-
-def test_recommend_next_steps_all_clear_when_nothing_wrong():
-    status = r.key_status(**_kw())
-    steps = r.recommend_next_steps([status])
-    assert steps == ["Everything is consistent -- no action needed."]
-
-
-def test_recommend_next_steps_release_key_has_no_catalog_signature_advice():
-    """A mismatched RELEASE key must never trigger catalog-signing advice --
-    the two keys' remediation paths must not bleed into each other."""
-    status = r.key_status(
-        kind="release",
-        display_name="RELEASE",
-        purpose="Signs checksums.",
-        private_key_location="on this machine",
-        local_exists=True,
-        local_pubkey=b"\x06" * 32,
-        locations=[("scripts/sign_checksums.py RELEASE_PUBKEYS", [b"\x07" * 32])],
-        catalog_sig_status=None,
-    )
-    steps = r.recommend_next_steps([status])
-    assert not any("re-signing" in s for s in steps)
-    assert any("RELEASE" in s for s in steps)
-
-
-def test_render_key_status_report_never_prints_private_key_material():
-    """The report string must be built ONLY from public inputs. Sanity
-    check: no field on KeyStatus/PubkeyLocationCheck is capable of holding
-    private key bytes in the first place (there's no such field to leak),
-    and the render function only touches fields that exist -- this test
-    guards against a future field addition reintroducing that risk."""
-    status = r.key_status(**_kw())
-    text = r.render_key_status_report([status])
-    assert "CATALOG" in text
-    assert (
-        "purpose" not in text.lower() or "Signs the catalog." in text
-    )  # sanity, not a real secret
-    # No 64-hex-char (or longer) run anywhere -- a raw 32-byte seed/sig
-    # would show up as one if it were ever accidentally interpolated in.
-    import re as _re
-
-    assert not _re.search(r"[0-9a-fA-F]{64,}", text)
-
-
-def test_render_key_status_report_names_the_specific_key_not_generic_the_key():
-    status = r.key_status(**_kw())
-    text = r.render_key_status_report([status])
-    assert "CATALOG KEY" in text
-    assert "the key" not in text.lower()
-
-
-def test_render_key_status_report_includes_catalog_signature_line_only_for_catalog():
-    catalog_status = r.key_status(**_kw())
-    release_status = r.key_status(
-        kind="release",
-        display_name="RELEASE",
-        purpose="Signs checksums.",
-        private_key_location="on this machine",
-        local_exists=True,
-        local_pubkey=b"\x08" * 32,
-        locations=[("scripts/sign_checksums.py RELEASE_PUBKEYS", [b"\x08" * 32])],
-        catalog_sig_status=None,
-    )
-    text = r.render_key_status_report([catalog_status, release_status])
-    assert text.count("Catalog signature:") == 1
-
-
-def test_render_key_status_report_ends_with_what_to_do_next_section():
-    status = r.key_status(**_kw())
-    text = r.render_key_status_report([status])
-    assert "What to do next:" in text

tests/test_core.py

@@ -1,6 +1,7 @@
 """Pytest port of the original test_core.py script (same 23 behaviours, now
 proper test functions with tmp_path/monkeypatch fixtures)."""
 
+import dataclasses
 import json
 import os
 import re
@@ -2370,3 +2371,447 @@ def test_config_has_unfilled_placeholders_false_after_fill():
 def test_config_has_unfilled_placeholders_checks_env_too():
     cfg = {"command": "uvx", "args": ["mcp-grafana"], "env": {"GRAFANA_URL": "<GRAFANA_URL>"}}
     assert c.config_has_unfilled_placeholders(cfg) is True
+
+
+# --------------------------------------------------------------------------- #
+# #72 -- a server value that isn't a JSON object must not take the load down
+# --------------------------------------------------------------------------- #
+@pytest.mark.parametrize("bad", ["not-a-dict", 123, ["a", "b"], None, True, 1.5])
+def test_extract_servers_survives_non_dict_server_value(bad):
+    entries = c.extract_servers({"mcpServers": {"foo": bad}})
+    assert len(entries) == 1
+    assert entries[0].name == "foo"
+    assert entries[0].data == {}
+    assert entries[0].malformed is True
+    assert entries[0].raw == bad
+
+
+def test_extract_servers_marks_only_the_bad_entry():
+    cfg = {"mcpServers": {"good": {"command": "npx"}, "bad": "oops"}}
+    by_name = {e.name: e for e in c.extract_servers(cfg)}
+    assert by_name["good"].malformed is False
+    assert by_name["good"].data == {"command": "npx"}
+    assert by_name["bad"].malformed is True
+
+
+def test_extract_servers_handles_malformed_disabled_entry():
+    entries = c.extract_servers({c.DISABLED_KEY: {"parked": ["nope"]}})
+    assert entries[0].enabled is False
+    assert entries[0].malformed is True
+
+
+def test_malformed_entry_round_trips_through_save_unchanged():
+    """The cardinal rule: never silently delete what the user had on disk."""
+    cfg = {"mcpServers": {"good": {"command": "npx"}, "bad": "oops"}}
+    servers = c.extract_servers(cfg)
+    out = c.apply_servers(dict(cfg), servers)
+    assert out["mcpServers"]["bad"] == "oops"
+    assert out["mcpServers"]["good"] == {"command": "npx"}
+
+
+def test_editing_a_malformed_entry_retires_the_raw_value():
+    entry = c.extract_servers({"mcpServers": {"bad": "oops"}})[0]
+    entry.set_data({"command": "npx"})
+    assert entry.malformed is False
+    assert entry.config_value() == {"command": "npx"}
+    assert c.apply_servers({}, [entry])["mcpServers"]["bad"] == {"command": "npx"}
+
+
+def test_lint_reports_the_malformed_entry_by_name():
+    servers = c.extract_servers({"mcpServers": {"bad": "oops"}})
+    warnings = c.lint_servers(servers)
+    assert len(warnings) == 1
+    assert "'bad'" in warnings[0]
+    assert "not an object" in warnings[0]
+    assert "str" in warnings[0]
+
+
+def test_lint_still_reports_normal_warnings_alongside_malformed():
+    cfg = {"mcpServers": {"bad": "oops", "sloppy": {"command": "npx", "args": "one two"}}}
+    warnings = c.lint_servers(c.extract_servers(cfg))
+    assert any("not an object" in w for w in warnings)
+    assert any("'args' should be a list" in w for w in warnings)
+
+
+# --------------------------------------------------------------------------- #
+# #73 -- the stale-file merge must not discard BCC-authored keys
+# --------------------------------------------------------------------------- #
+def test_carry_owned_keys_moves_sets_onto_the_reloaded_config():
+    local = {"mcpServers": {}, c.SETS_KEY: {"work": ["a", "b"]}}
+    fresh = {"mcpServers": {"external": {"command": "npx"}}}
+    contested = c.carry_owned_keys(local, fresh)
+    assert contested == []
+    assert fresh[c.SETS_KEY] == {"work": ["a", "b"]}
+    assert fresh["mcpServers"] == {"external": {"command": "npx"}}
+
+
+def test_carry_owned_keys_reports_a_genuine_conflict():
+    local = {c.SETS_KEY: {"work": ["a"]}}
+    fresh = {c.SETS_KEY: {"work": ["a", "b"]}}
+    assert c.carry_owned_keys(local, fresh) == [c.SETS_KEY]
+    assert fresh[c.SETS_KEY] == {"work": ["a"]}  # local wins: BCC owns the key
+
+
+def test_carry_owned_keys_is_quiet_when_both_sides_agree():
+    local = {c.SETS_KEY: {"work": ["a"]}}
+    fresh = {c.SETS_KEY: {"work": ["a"]}}
+    assert c.carry_owned_keys(local, fresh) == []
+
+
+def test_carry_owned_keys_leaves_disk_alone_when_absent_locally():
+    """Can't distinguish 'deleted my last set' from 'never had sets'; keep theirs."""
+    fresh = {c.SETS_KEY: {"remote": ["a"]}}
+    assert c.carry_owned_keys({}, fresh) == []
+    assert fresh[c.SETS_KEY] == {"remote": ["a"]}
+
+
+def test_carry_owned_keys_deep_copies_so_later_edits_do_not_leak():
+    local = {c.SETS_KEY: {"work": ["a"]}}
+    fresh = {}
+    c.carry_owned_keys(local, fresh)
+    local[c.SETS_KEY]["work"].append("b")
+    assert fresh[c.SETS_KEY] == {"work": ["a"]}
+
+
+def test_merge_flow_preserves_sets_and_external_servers(tmp_path):
+    """End-to-end shape of the Merge & save path that lost sets in #73."""
+    path = tmp_path / "claude.json"
+    path.write_text(json.dumps({"mcpServers": {"old": {"command": "old"}}}))
+
+    # BCC loads, user saves a named set and edits servers in memory.
+    local = c.load_config(path)
+    servers = c.extract_servers(local)
+    c.save_server_set(local, "work", servers)
+
+    # Something else rewrites the file underneath us.
+    path.write_text(json.dumps({"mcpServers": {"external": {"command": "new"}}, "other": 1}))
+
+    # Merge & save: reload disk, carry BCC keys, re-apply the user's servers.
+    fresh = c.load_config(path)
+    c.carry_owned_keys(local, fresh)
+    c.apply_servers(fresh, servers)
+    c.write_config(path, fresh)
+
+    saved = c.load_config(path)
+    assert saved[c.SETS_KEY] == {"work": ["old"]}  # the set survived
+    assert saved["other"] == 1  # unrelated external key preserved
+    assert "old" in saved["mcpServers"]  # user's servers re-applied
+
+
+def test_null_server_value_is_malformed_not_mistaken_for_absent():
+    """`{"mcpServers": {"foo": null}}` is legal JSON and a real malformed case,
+    so None must not double as the 'nothing here' sentinel."""
+    entry = c.extract_servers({"mcpServers": {"foo": None}})[0]
+    assert entry.malformed is True
+    assert entry.raw is None
+    assert c.apply_servers({}, [entry])["mcpServers"]["foo"] is None
+
+
+def test_a_normal_entry_is_not_malformed():
+    entry = c.extract_servers({"mcpServers": {"foo": {"command": "npx"}}})[0]
+    assert entry.malformed is False
+    assert entry.raw is c.NO_RAW
+
+
+# --------------------------------------------------------------------------- #
+# #75 -- theming
+# --------------------------------------------------------------------------- #
+@pytest.mark.parametrize(
+    "setting,system_dark,expected",
+    [
+        (c.THEME_DARK, False, "dark"),
+        (c.THEME_DARK, True, "dark"),
+        (c.THEME_LIGHT, False, "light"),
+        (c.THEME_LIGHT, True, "light"),
+        (c.THEME_SYSTEM, True, "dark"),
+        (c.THEME_SYSTEM, False, "light"),
+    ],
+)
+def test_resolve_theme_covers_every_setting_and_appearance(setting, system_dark, expected):
+    assert c.resolve_theme(setting, system_dark) == expected
+
+
+@pytest.mark.parametrize("junk", ["", "solarized", None, "DARK", 3])
+def test_resolve_theme_falls_back_to_following_the_system(junk):
+    """A hand-edited or future QSettings value should follow the desktop,
+    not pin a fixed theme."""
+    assert c.resolve_theme(junk, True) == "dark"
+    assert c.resolve_theme(junk, False) == "light"
+
+
+def test_palette_for_known_names():
+    assert c.palette_for("dark") is c.DARK_PALETTE
+    assert c.palette_for("light") is c.LIGHT_PALETTE
+
+
+def test_palette_for_unknown_name_falls_back_to_dark():
+    assert c.palette_for("chartreuse") is c.DARK_PALETTE
+
+
+def test_dark_palette_is_unchanged_from_the_shipped_look():
+    """v1.3.0 shipped these exact colours; adding a light theme must not
+    quietly restyle the dark one."""
+    p = c.DARK_PALETTE
+    assert (p.accent, p.bg, p.panel, p.panel_2) == ("#f97316", "#1b1d23", "#23262e", "#2b2f39")
+    assert (p.text, p.muted, p.border) == ("#e7e9ee", "#9aa0ad", "#3a3f4b")
+    assert (p.good, p.bad, p.warn, p.remote) == ("#4ade80", "#f87171", "#fbbf24", "#60a5fa")
+    assert (p.on_accent, p.disabled_bg, p.mono_bg) == ("#1a1205", "#202229", "#16181d")
+
+
+def test_both_palettes_define_every_slot():
+    """A missing slot should fail here rather than render a broken window."""
+    for pal in (c.DARK_PALETTE, c.LIGHT_PALETTE):
+        for f in dataclasses.fields(c.Palette):
+            value = getattr(pal, f.name)
+            assert value, f"{pal.name}.{f.name} is empty"
+            if f.name != "name":
+                assert re.fullmatch(r"#[0-9a-fA-F]{6}", value), f"{pal.name}.{f.name}={value!r}"
+
+
+@pytest.mark.parametrize("pal_name", ["dark", "light"])
+@pytest.mark.parametrize("slot", ["text", "muted", "good", "bad", "warn", "remote", "accent"])
+def test_palette_meets_contrast_on_panel(pal_name, slot):
+    """Every colour drawn as text/glyph must clear WCAG AA (4.5:1) against the
+    surface it sits on. The light palette's semantic colours are NOT the dark
+    ones lightened -- #4ade80 sits near 1.7:1 on white -- so this guards
+    against someone 'harmonising' them back toward the dark hues."""
+    pal = c.palette_for(pal_name)
+    assert c.contrast_ratio(getattr(pal, slot), pal.panel) >= 4.5
+
+
+@pytest.mark.parametrize("pal_name", ["dark", "light"])
+def test_on_accent_is_legible_against_the_accent_fill(pal_name):
+    """Primary buttons and selected rows draw on_accent on top of accent."""
+    pal = c.palette_for(pal_name)
+    assert c.contrast_ratio(pal.on_accent, pal.accent) >= 4.5
+
+
+def test_contrast_ratio_endpoints():
+    assert c.contrast_ratio("#000000", "#ffffff") == pytest.approx(21.0, abs=0.01)
+    assert c.contrast_ratio("#123456", "#123456") == pytest.approx(1.0, abs=0.001)
+    assert c.contrast_ratio("#ffffff", "#000000") == pytest.approx(21.0, abs=0.01)
+
+
+def test_relative_luminance_extremes():
+    assert c.relative_luminance("#000000") == pytest.approx(0.0)
+    assert c.relative_luminance("#ffffff") == pytest.approx(1.0)
+
+
+def test_stylesheet_builder_has_no_hardcoded_colours():
+    """Every colour in the QSS must come from the palette.
+
+    Three near-black literals used to be inlined here (#1a1205, #202229,
+    #16181d). Harmless with one theme; with two, they silently render dark
+    chrome on a light window. Reads the source rather than importing bcc,
+    which needs PySide6.
+    """
+    src = (Path(__file__).resolve().parent.parent / "bcc.py").read_text(encoding="utf-8")
+    start = src.index("def build_stylesheet")
+    body = src[start : src.index("def apply_palette")]
+    assert re.findall(r"#[0-9a-fA-F]{6}", body) == []
+
+
+def test_every_palette_slot_is_consumed():
+    """A slot added to Palette but never wired up is dead weight.
+
+    Checks for `p.<slot>` anywhere in bcc.py, which covers both the QSS and
+    apply_palette's global bindings -- not every slot belongs in the
+    stylesheet (`good` and `remote` feed the inline status dots via
+    STATUS_COLORS/HEALTH_COLORS, never the QSS). This won't catch a slot bound
+    to a global that nothing then uses; it does catch the common mistake of
+    extending the dataclass and forgetting to plumb it through.
+    """
+    src = (Path(__file__).resolve().parent.parent / "bcc.py").read_text(encoding="utf-8")
+    for f in dataclasses.fields(c.Palette):
+        if f.name == "name":
+            continue
+        assert f"p.{f.name}" in src, f"palette slot {f.name!r} is never consumed"
+
+
+# --------------------------------------------------------------------------- #
+# #78/#79 -- update notice: when to show it, and what it says
+# --------------------------------------------------------------------------- #
+def test_update_notice_when_a_newer_release_exists():
+    n = c.update_notice("1.2.0", {"version": "v1.3.0", "url": "https://example.test/rel"})
+    assert n is not None
+    assert n["version"] == "v1.3.0"
+    assert n["url"] == "https://example.test/rel"
+    assert "1.3.0" in n["text"] and "1.2.0" in n["text"]
+
+
+def test_update_notice_is_silent_when_current():
+    assert c.update_notice("1.3.0", {"version": "v1.3.0"}) is None
+    assert c.update_notice("1.4.0", {"version": "v1.3.0"}) is None
+
+
+@pytest.mark.parametrize("bad", [None, {}, {"version": ""}, {"version": None}, {"version": 3}, []])
+def test_update_notice_is_silent_on_a_failed_or_malformed_check(bad):
+    """fetch_latest_release returns None on any failure; a half-formed payload
+    must not produce a notice pointing at nothing."""
+    assert c.update_notice("1.0.0", bad) is None
+
+
+def test_update_notice_falls_back_to_the_releases_page_without_a_url():
+    n = c.update_notice("1.0.0", {"version": "v2.0.0"})
+    assert n["url"] == c.RELEASES_URL
+
+
+def test_update_notice_names_no_menu_path():
+    """The old status-line text said 'Help > About to view it', which is wrong
+    on macOS -- Qt moves the About action into the application menu (#79). The
+    notice carries its own action, so it must not describe a menu path."""
+    n = c.update_notice("1.0.0", {"version": "v2.0.0"})
+    lowered = n["text"].lower()
+    for phrase in ("help", "about", "menu", "▸", ">"):
+        assert phrase not in lowered, f"notice text should not reference {phrase!r}"
+
+
+def test_update_notice_handles_the_v_prefix_consistently():
+    assert c.update_notice("1.2.0", {"version": "1.3.0"}) is not None
+    assert c.update_notice("v1.2.0", {"version": "v1.3.0"}) is not None
+    assert c.update_notice("1.3.0", {"version": "v1.3.0"}) is None
+
+
+def test_update_notice_renders_both_versions_the_same_way():
+    """Tags carry a 'v' prefix, __version__ doesn't -- don't show both forms
+    in one sentence."""
+    n = c.update_notice("1.2.0", {"version": "v1.3.0"})
+    assert "v1.3.0" not in n["text"]
+    assert "1.3.0" in n["text"] and "1.2.0" in n["text"]
+    # the machine-readable field keeps the real tag
+    assert n["version"] == "v1.3.0"
+
+
+# --------------------------------------------------------------------------- #
+# #76 -- ${VAR} references. Semantics mirror Claude Code's documented
+# behaviour: ${VAR} and ${VAR:-default}, expanded in command/args/env/url/
+# headers, and an unset variable with no default left as literal text.
+# --------------------------------------------------------------------------- #
+def test_find_env_refs_plain_and_defaulted():
+    refs = c.find_env_refs("${A} and ${B:-fallback}")
+    assert [(r.name, r.default) for r in refs] == [("A", None), ("B", "fallback")]
+
+
+@pytest.mark.parametrize("text", ["${}", "${1BAD}", "$NOTBRACED", "{NOPE}", "plain", "$${X"])
+def test_find_env_refs_ignores_non_references(text):
+    assert c.find_env_refs(text) == []
+
+
+def test_find_env_refs_allows_an_empty_default():
+    """`${VAR:-}` is a documented way to say 'blank if unset'."""
+    refs = c.find_env_refs("${A:-}")
+    assert refs[0].default == ""
+    assert refs[0].has_default is True
+
+
+def test_server_env_refs_covers_all_five_documented_fields():
+    data = {
+        "command": "${BIN}",
+        "args": ["--x", "${ARG}"],
+        "env": {"K": "${ENVV}"},
+        "url": "${URL}/mcp",
+        "headers": {"Authorization": "Bearer ${HDR}"},
+    }
+    found = {(r.name, r.field) for r in c.server_env_refs(data)}
+    assert found == {
+        ("BIN", "command"),
+        ("ARG", "args"),
+        ("ENVV", "env"),
+        ("URL", "url"),
+        ("HDR", "headers"),
+    }
+
+
+def test_server_env_refs_ignores_unexpanded_fields():
+    """Claude Code expands five fields; a ${VAR} elsewhere isn't a reference."""
+    assert c.server_env_refs({"description": "${NOPE}", "timeout": "${ALSO_NO}"}) == []
+
+
+def test_expand_env_refs_matches_documented_semantics():
+    env = {"SET": "value"}
+    assert c.expand_env_refs("${SET}", env) == "value"
+    assert c.expand_env_refs("${MISSING:-dflt}", env) == "dflt"
+    assert c.expand_env_refs("${SET:-dflt}", env) == "value"
+    # unset with no default: left as literal text, exactly as Claude Code does
+    assert c.expand_env_refs("${MISSING}", env) == "${MISSING}"
+
+
+def test_expand_env_refs_handles_several_in_one_string():
+    assert c.expand_env_refs("${A}/${B:-two}/${C}", {"A": "one"}) == "one/two/${C}"
+
+
+def test_unresolved_env_refs_only_flags_unset_without_default():
+    data = {"env": {"A": "${SET}", "B": "${UNSET}", "C": "${OTHER:-has_default}"}}
+    assert [r.name for r in c.unresolved_env_refs(data, {"SET": "x"})] == ["UNSET"]
+
+
+# --- the two interactions that were backwards for this feature ------------
+def test_placeholder_under_a_secret_key_is_not_masked():
+    """A ${VAR} names a secret rather than being one. Masking it would make a
+    reference indistinguishable from a stored credential."""
+    assert c.should_mask_value("API_KEY", "${API_KEY}") is False
+    assert c.should_mask_value("API_KEY", "ghp_realsecret") is True
+    assert c.should_mask_value("NOT_SECRET", "${API_KEY}") is False
+
+
+def test_redacted_display_keeps_placeholders_but_masks_real_secrets():
+    out = c._redact_server_data({"env": {"API_KEY": "${API_KEY}", "TOKEN": "ghp_real"}})
+    assert out["env"]["API_KEY"] == "${API_KEY}"
+    assert out["env"]["TOKEN"] == c.MASK
+
+
+def test_redact_args_keeps_placeholders_visible():
+    assert c.redact_args(["--token", "${GH_TOKEN}"]) == ["--token", "${GH_TOKEN}"]
+    assert c.redact_args(["--api-key=${K}"]) == ["--api-key=${K}"]
+    # real secrets still masked
+    assert c.redact_args(["--token", "ghp_real"]) == ["--token", c.MASK]
+    assert c.redact_args(["--api-key=sk-real"]) == [f"--api-key={c.MASK}"]
+
+
+def test_args_secret_warning_is_silenced_by_a_placeholder():
+    """Moving a token into ${VAR} is the recommended fix for this warning --
+    still warning afterwards would punish the fix."""
+    assert c.args_secret_warning({"args": ["--token", "ghp_real"]}) is not None
+    assert c.args_secret_warning({"args": ["--token", "${GH_TOKEN}"]}) is None
+
+
+def test_args_secret_warning_still_fires_on_the_arg_after_a_placeholder():
+    """A placeholder must clear the pending-flag state, not blanket-suppress."""
+    assert c.args_secret_warning({"args": ["${SAFE}", "--token", "ghp_real"]}) is not None
+
+
+# --- per-client gating ----------------------------------------------------
+def _profile(path):
+    return c.Profile(label="p", path=Path(path), config_exists=True)
+
+
+def test_claude_code_profiles_expand_references():
+    assert c.client_expands_env_refs(_profile(Path.home() / ".claude.json")) is True
+    assert c.client_expands_env_refs(_profile("/repo/.mcp.json")) is True
+
+
+def test_claude_desktop_profile_does_not_expand_references():
+    desktop = _profile(c.app_support_base() / "Claude" / c.CONFIG_FILENAME)
+    assert c.client_expands_env_refs(desktop) is False
+
+
+def test_desktop_profile_warns_that_references_are_literal():
+    data = {"env": {"API_KEY": "${API_KEY}"}}
+    desktop = _profile(c.app_support_base() / "Claude" / c.CONFIG_FILENAME)
+    warnings = c.env_ref_warnings(data, desktop, {"API_KEY": "set"})
+    assert len(warnings) == 1
+    assert "NOT be expanded" in warnings[0]
+    assert "${API_KEY}" in warnings[0]
+
+
+def test_claude_code_profile_warns_only_about_unset_variables():
+    code = _profile(Path.home() / ".claude.json")
+    data = {"env": {"A": "${UNSET_ONE}"}}
+    assert c.env_ref_warnings(data, code, {}) != []
+    assert c.env_ref_warnings(data, code, {"UNSET_ONE": "x"}) == []
+    # a default means it always resolves
+    assert c.env_ref_warnings({"env": {"A": "${X:-d}"}}, code, {}) == []
+
+
+def test_no_references_means_no_warnings():
+    assert c.env_ref_warnings({"command": "npx", "args": ["-y", "pkg"]}, None) == []