fix: MSIX warning gets a persistent banner instead of the status bar (#35)

The status bar is rewritten on every action, so the appended MSIX
warning vanished on first interaction. A dedicated warn banner under
the top bar stays visible.

Closes #35

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

bcc.py

@@ -125,6 +125,7 @@ QScrollBar:vertical {{ background: transparent; width: 10px; margin: 2px; }}
 QScrollBar::handle:vertical {{ background: {BORDER}; border-radius: 5px; min-height: 24px; }}
 QScrollBar::add-line, QScrollBar::sub-line {{ height: 0; }}
 QLabel#statusbar {{ color: {MUTED}; padding: 4px 2px; }}
+QLabel#warnBanner {{ color: #1a1205; background: {WARN}; border-radius: 8px; padding: 8px 10px; font-weight: 600; }}
 QLabel#section {{ color: {MUTED}; font-weight: 600; font-size: 12px; padding: 2px 2px; }}
 QLabel#sectionDisabled {{ color: {MUTED}; font-weight: 600; font-size: 12px; padding: 2px 2px; }}
 QLabel#placeholder {{ color: {MUTED}; padding: 12px; background: {PANEL_2}; border: 1px dashed {BORDER}; border-radius: 8px; }}
@@ -1496,6 +1497,15 @@ class MainWindow(QMainWindow):
 
         root.addLayout(self._build_topbar())
 
+        # Persistent warning banner (MSIX-virtualized config, etc.). Lives in
+        # its own widget because the status bar is rewritten on every action,
+        # which used to wipe the warning before the user could read it.
+        self.warn_banner = QLabel("")
+        self.warn_banner.setObjectName("warnBanner")
+        self.warn_banner.setWordWrap(True)
+        self.warn_banner.hide()
+        root.addWidget(self.warn_banner)
+
         # User-draggable divider between the server list and the editor.
         split = QSplitter(Qt.Orientation.Horizontal)
         split.setChildrenCollapsible(False)
@@ -1770,8 +1780,9 @@ class MainWindow(QMainWindow):
     def _maybe_warn_msix(self):
         """
         Windows-only, no-op everywhere else: if Claude Desktop looks like an
-        MSIX/Store install with a virtualized config, append a warning to the
+        MSIX/Store install with a virtualized config, show a persistent banner
-        status bar so edits to the plain %APPDATA% path aren't silently lost.
+        so edits to the plain %APPDATA% path aren't silently lost. (The status
+        bar is the wrong home for this: it's rewritten on every action.)
         Defensive on purpose -- this must never block startup or profile load.
         """
         try:
@@ -1779,8 +1790,11 @@ class MainWindow(QMainWindow):
         except Exception:
             return
         if warning:
-            self.status.setText(f"{self.status.text()}  ⚠ {warning}")
+            self.warn_banner.setText(f"⚠  {warning}")
-            self.status.setToolTip(warning)
+            self.warn_banner.setToolTip(warning)
+            self.warn_banner.show()
+        else:
+            self.warn_banner.hide()
 
     def add_custom_config(self):
         start = str(core.app_support_base())