chore: extend gitignore for wails build artifacts

Ignore Wails task cache, compiled binaries, and platform-specific
generated build outputs while keeping committed bindings and build
metadata.

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitignore

@@ -1,3 +1,11 @@
 .DS_Store
+.task/
+bin/
 frontend/node_modules/
 frontend/dist/
+build/linux/appimage/build
+build/windows/nsis/MicrosoftEdgeWebview2Setup.exe
+build/ios/xcode/overlay.json
+build/ios/xcode/gen/
+build/android/overlay.json
+build/android/gen/