feat: GStack Browser icon — custom .icns replaces Chromium's Dock icon

- Generated 1024px icon: dark terminal window with amber prompt cursor
- Converted to .icns with all macOS sizes (16-1024px, 1x and 2x)
- build-app.sh copies icon into both the outer .app and bundled Chromium's
  Resources (Chromium's process owns the Dock icon, not the launcher)
- browser-manager.ts patches Chromium's icon at runtime for dev mode too
- Both the Dock and Cmd+Tab now show the GStack icon

browse/src/browser-manager.ts

@@ -277,6 +277,21 @@ export class BrowserManager {
             .replace(/Google Chrome for Testing/g, 'GStack Browser');
           fs.writeFileSync(chromePlist, patched);
         }
+        // Replace Chromium's Dock icon with ours (Chromium's process owns the Dock icon)
+        const iconCandidates = [
+          path.join(__dirname, '..', '..', 'scripts', 'app', 'icon.icns'),       // repo dev mode
+          path.join(process.env.HOME || '', '.claude', 'skills', 'gstack', 'scripts', 'app', 'icon.icns'), // global install
+        ];
+        const iconSrc = iconCandidates.find(p => fs.existsSync(p));
+        if (iconSrc) {
+          const chromeResources = path.join(chromeContentsDir, 'Resources');
+          // Read original icon name from plist
+          const iconMatch = plistContent.match(/<key>CFBundleIconFile<\/key>\s*<string>([^<]+)<\/string>/);
+          let origIcon = iconMatch ? iconMatch[1] : 'app';
+          if (!origIcon.endsWith('.icns')) origIcon += '.icns';
+          const destIcon = path.join(chromeResources, origIcon);
+          try { fs.copyFileSync(iconSrc, destIcon); } catch { /* non-fatal */ }
+        }
       }
     } catch {
       // Non-fatal: app name just stays as Chrome for Testing

scripts/build-app.sh

@@ -96,6 +96,27 @@ if [ -f "$CHROMIUM_PLIST" ]; then
     plutil -convert xml1 "$CHROMIUM_STRINGS" 2>/dev/null || true
     sed -i '' "s/Google Chrome for Testing/$APP_NAME/g" "$CHROMIUM_STRINGS" 2>/dev/null || true
   fi
+  # Replace Chromium's icon with ours so the Dock shows the GStack icon
+  # (Chromium's process owns the Dock icon, not our launcher)
+  ICON_SRC="$SCRIPT_DIR/app/icon.icns"
+  if [ -f "$ICON_SRC" ]; then
+    CHROMIUM_RESOURCES="$APP_DIR/Contents/Resources/chromium/$(basename "$CHROME_APP")/Contents/Resources"
+    # Find the original icon filename from Chromium's plist
+    ORIG_ICON=$(/usr/libexec/PlistBuddy -c "Print :CFBundleIconFile" "$CHROMIUM_PLIST" 2>/dev/null || echo "app")
+    # Add .icns extension if not present
+    [[ "$ORIG_ICON" != *.icns ]] && ORIG_ICON="${ORIG_ICON}.icns"
+    cp "$ICON_SRC" "$CHROMIUM_RESOURCES/$ORIG_ICON"
+    echo "  Replaced Chromium icon → $ORIG_ICON"
+  fi
+fi
+
+# ─── Step 3c: App icon ────────────────────────────────────────────
+ICON_SRC="$SCRIPT_DIR/app/icon.icns"
+if [ -f "$ICON_SRC" ]; then
+  cp "$ICON_SRC" "$APP_DIR/Contents/Resources/icon.icns"
+  echo "  App icon installed"
+else
+  echo "  WARNING: No icon.icns found at $ICON_SRC — app will use default icon"
 fi
 
 # ─── Step 4: Info.plist ──────────────────────────────────────────