feat: About dialog with menu bar + notify-only update checker UI (#18, #19)

- Add a real QMenuBar (Help -> About...).
- AboutDialog: app icon, name, version (core.__version__), and links to the
  repo/issues/license opened via QDesktopServices.openUrl (system browser,
  never in-app navigation). macOS unsigned-app note.
- "Check for updates" button + UpdateCheckWorker (QThread) runs
  core.fetch_latest_release() off the UI thread; shows "up to date" or
  "vX.Y.Z available" with a button to open the releases page. No binary
  download, ever.
- Optional quiet startup auto-check, throttled to once/day via a QSettings
  timestamp, off-thread, silent on failure, toggle lives in the About dialog.

bcc.py

@@ -11,13 +11,23 @@ Run:  python mcp_manager.py
 from __future__ import annotations
 
 import sys
+import time
 from pathlib import Path
 
-from PySide6.QtCore import QRect, QSettings, QSize, Qt, QThread, QTimer, Signal
+from PySide6.QtCore import QRect, QSettings, QSize, Qt, QThread, QTimer, QUrl, Signal
-from PySide6.QtGui import QAction, QColor, QGuiApplication, QPainter
+from PySide6.QtGui import (
+    QAction,
+    QColor,
+    QDesktopServices,
+    QGuiApplication,
+    QIcon,
+    QPainter,
+    QPixmap,
+)
 from PySide6.QtWidgets import (
     QAbstractItemView,
     QApplication,
+    QCheckBox,
     QComboBox,
     QDialog,
     QDialogButtonBox,
@@ -147,6 +157,23 @@ class SpawnTester(QThread):
         self.done.emit(result)
 
 
+class UpdateCheckWorker(QThread):
+    """
+    Fetches the latest release from the Gitea releases API off the UI thread.
+
+    Notify-only: `core.fetch_latest_release()` only ever reads release
+    metadata (a version tag + a URL) and never downloads or replaces the
+    running binary. Fails quiet — emits None on any network problem — so
+    it's safe to fire unattended from a silent startup check as well as from
+    the About dialog's "Check for updates" button.
+    """
+
+    done = Signal(object)  # dict | None
+
+    def run(self):
+        self.done.emit(core.fetch_latest_release())
+
+
 # --------------------------------------------------------------------------- #
 # Small reusable: key/value editor (for env and headers)
 # --------------------------------------------------------------------------- #
@@ -1090,6 +1117,153 @@ class PasteDialog(QDialog):
             self.err.setText(str(e))
 
 
+# --------------------------------------------------------------------------- #
+# About dialog
+# --------------------------------------------------------------------------- #
+class AboutDialog(QDialog):
+    """
+    App info + a manual "Check for updates" action.
+
+    Shows nothing sensitive: app name, icon, version (from
+    core.__version__), and links opened in the system browser via
+    QDesktopServices.openUrl — never navigated to in-app. The update check
+    itself only ever reads release metadata (see UpdateCheckWorker); it
+    never downloads or replaces the running binary.
+    """
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setWindowTitle("About Better Claude Config")
+        self.setFixedWidth(440)
+        self._worker: UpdateCheckWorker | None = None
+        self._release_url: str | None = None
+
+        icon_path = (
+            Path(__file__).resolve().parent / "icons" / "twin-gears" / "rounded" / "icon-128.png"
+        )
+        if icon_path.is_file():
+            self.setWindowIcon(QIcon(str(icon_path)))
+
+        v = QVBoxLayout(self)
+        v.setSpacing(10)
+
+        head = QHBoxLayout()
+        head.setSpacing(12)
+        icon_lbl = QLabel()
+        if icon_path.is_file():
+            icon_lbl.setPixmap(
+                QPixmap(str(icon_path)).scaled(
+                    56,
+                    56,
+                    Qt.AspectRatioMode.KeepAspectRatio,
+                    Qt.TransformationMode.SmoothTransformation,
+                )
+            )
+        head.addWidget(icon_lbl)
+
+        title_box = QVBoxLayout()
+        title_box.setSpacing(2)
+        name_lbl = QLabel("Better Claude Config")
+        name_lbl.setObjectName("h1")
+        title_box.addWidget(name_lbl)
+        ver_lbl = QLabel(f"Version {core.__version__}")
+        ver_lbl.setObjectName("muted")
+        title_box.addWidget(ver_lbl)
+        head.addLayout(title_box, 1)
+        v.addLayout(head)
+
+        desc = QLabel(
+            "A cross-platform GUI for editing the mcpServers block of Claude "
+            "Desktop and Claude Code configs."
+        )
+        desc.setObjectName("muted")
+        desc.setWordWrap(True)
+        v.addWidget(desc)
+
+        if sys.platform == "darwin":
+            note = QLabel(
+                "This build isn't notarized by Apple. If macOS blocks it on first "
+                "launch, right-click the app  ▸  Open, or allow it under System "
+                "Settings  ▸  Privacy & Security."
+            )
+            note.setObjectName("muted")
+            note.setWordWrap(True)
+            v.addWidget(note)
+
+        links = QHBoxLayout()
+        for text, url in (
+            ("Repository", core.REPO_URL),
+            ("Issues", core.ISSUES_URL),
+            ("MIT License", core.LICENSE_URL),
+        ):
+            btn = QPushButton(text)
+            btn.setFlat(True)
+            btn.setCursor(Qt.CursorShape.PointingHandCursor)
+            btn.clicked.connect(lambda _=False, u=url: QDesktopServices.openUrl(QUrl(u)))
+            links.addWidget(btn)
+        links.addStretch()
+        v.addLayout(links)
+
+        # --- update check ----------------------------------------------- #
+        upd_row = QHBoxLayout()
+        self.check_btn = QPushButton("Check for updates")
+        self.check_btn.clicked.connect(self._check_for_updates)
+        upd_row.addWidget(self.check_btn)
+        self.update_status = QLabel("")
+        self.update_status.setObjectName("muted")
+        self.update_status.setWordWrap(True)
+        upd_row.addWidget(self.update_status, 1)
+        v.addLayout(upd_row)
+
+        self.release_btn = QPushButton("Open releases page")
+        self.release_btn.setCursor(Qt.CursorShape.PointingHandCursor)
+        self.release_btn.clicked.connect(self._open_release_page)
+        self.release_btn.hide()
+        v.addWidget(self.release_btn)
+
+        self.auto_check_box = QCheckBox("Automatically check for updates on startup")
+        st = QSettings("BCC", "BetterClaudeConfig")
+        self.auto_check_box.setChecked(bool(st.value("update/autoCheck", True, type=bool)))
+        self.auto_check_box.toggled.connect(self._toggle_auto_check)
+        v.addWidget(self.auto_check_box)
+
+        btns = QDialogButtonBox(QDialogButtonBox.StandardButton.Close)
+        btns.rejected.connect(self.reject)
+        btns.button(QDialogButtonBox.StandardButton.Close).clicked.connect(self.accept)
+        v.addWidget(btns)
+
+    def _toggle_auto_check(self, on: bool):
+        QSettings("BCC", "BetterClaudeConfig").setValue("update/autoCheck", on)
+
+    def _check_for_updates(self):
+        self.check_btn.setEnabled(False)
+        self.release_btn.hide()
+        self.update_status.setStyleSheet(f"color: {MUTED};")
+        self.update_status.setText("Checking…")
+        self._worker = UpdateCheckWorker()
+        self._worker.done.connect(self._on_check_done)
+        self._worker.start()
+
+    def _on_check_done(self, release: dict | None):
+        self.check_btn.setEnabled(True)
+        self._worker = None
+        if not release:
+            self.update_status.setStyleSheet(f"color: {MUTED};")
+            self.update_status.setText("Couldn't check for updates (offline?).")
+            return
+        if core.is_newer_version(core.__version__, release["version"]):
+            self.update_status.setStyleSheet(f"color: {ACCENT};")
+            self.update_status.setText(f"{release['version']} available.")
+            self._release_url = release.get("url") or core.RELEASES_URL
+            self.release_btn.show()
+        else:
+            self.update_status.setStyleSheet(f"color: {GOOD};")
+            self.update_status.setText("You're up to date.")
+
+    def _open_release_page(self):
+        QDesktopServices.openUrl(QUrl(self._release_url or core.RELEASES_URL))
+
+
 # --------------------------------------------------------------------------- #
 # Main window
 # --------------------------------------------------------------------------- #
@@ -1099,6 +1273,7 @@ class MainWindow(QMainWindow):
         self.setWindowTitle("Better Claude Config")
         self.resize(940, 640)
         self.setAcceptDrops(True)
+        self._build_menu_bar()
 
         self.profiles: list[core.Profile] = []
         self.full_config: dict = {}
@@ -1141,6 +1316,37 @@ class MainWindow(QMainWindow):
 
         self._restore_layout()
         self.reload_profiles()
+        self._maybe_auto_check_updates()
+
+    # --- menu bar ---------------------------------------------------------- #
+    def _build_menu_bar(self):
+        help_menu = self.menuBar().addMenu("&Help")
+        about_action = QAction("About Better Claude Config…", self)
+        about_action.triggered.connect(self._show_about)
+        help_menu.addAction(about_action)
+
+    def _show_about(self):
+        AboutDialog(self).exec()
+
+    # --- update check (silent, throttled, off-thread) --------------------- #
+    def _maybe_auto_check_updates(self):
+        st = QSettings("BCC", "BetterClaudeConfig")
+        if not bool(st.value("update/autoCheck", True, type=bool)):
+            return
+        last = float(st.value("update/lastCheck", 0.0, type=float) or 0.0)
+        if (time.time() - last) < 86400:  # at most once/day
+            return
+        st.setValue("update/lastCheck", time.time())
+        self._startup_update_worker = UpdateCheckWorker()
+        self._startup_update_worker.done.connect(self._on_startup_update_checked)
+        self._startup_update_worker.start()
+
+    def _on_startup_update_checked(self, release: dict | None):
+        self._startup_update_worker = None
+        if release and core.is_newer_version(core.__version__, release["version"]):
+            self.status.setText(
+                f"Update available: {release['version']}  ·  Help ▸ About to view it."
+            )
 
     # --- layout persistence ---------------------------------------------- #
     def _restore_layout(self):