chore: bring flutter client, docs, deploy and tools into monorepo

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

musify_flutter/.agents/skills/flutter-expert/references/performance.md

@@ -0,0 +1,99 @@
+# Performance Optimization
+
+## Profiling Commands
+
+```bash
+# Run in profile mode
+flutter run --profile
+
+# Analyze performance
+flutter analyze
+
+# DevTools
+flutter pub global activate devtools
+flutter pub global run devtools
+```
+
+## Common Optimizations
+
+### Const Widgets
+```dart
+// ❌ Rebuilds every time
+Widget build(BuildContext context) {
+  return Container(
+    padding: EdgeInsets.all(16),  // Creates new object
+    child: Text('Hello'),
+  );
+}
+
+// ✅ Const prevents rebuilds
+Widget build(BuildContext context) {
+  return Container(
+    padding: const EdgeInsets.all(16),
+    child: const Text('Hello'),
+  );
+}
+```
+
+### Selective Provider Watching
+```dart
+// ❌ Rebuilds on any user change
+final user = ref.watch(userProvider);
+return Text(user.name);
+
+// ✅ Only rebuilds when name changes
+final name = ref.watch(userProvider.select((u) => u.name));
+return Text(name);
+```
+
+### RepaintBoundary
+```dart
+// Isolate expensive widgets
+RepaintBoundary(
+  child: ComplexAnimatedWidget(),
+)
+```
+
+### Image Optimization
+```dart
+// Use cached_network_image
+CachedNetworkImage(
+  imageUrl: url,
+  placeholder: (_, __) => const CircularProgressIndicator(),
+  errorWidget: (_, __, ___) => const Icon(Icons.error),
+)
+
+// Resize images
+Image.network(
+  url,
+  cacheWidth: 200,  // Resize in memory
+  cacheHeight: 200,
+)
+```
+
+### Compute for Heavy Operations
+```dart
+// ❌ Blocks UI thread
+final result = heavyComputation(data);
+
+// ✅ Runs in isolate
+final result = await compute(heavyComputation, data);
+```
+
+## Performance Checklist
+
+| Check | Solution |
+|-------|----------|
+| Unnecessary rebuilds | Add `const`, use `select()` |
+| Large lists | Use `ListView.builder` |
+| Image loading | Use `cached_network_image` |
+| Heavy computation | Use `compute()` |
+| Jank in animations | Use `RepaintBoundary` |
+| Memory leaks | Dispose controllers |
+
+## DevTools Metrics
+
+- **Frame rendering time**: < 16ms for 60fps
+- **Widget rebuilds**: Minimize unnecessary rebuilds
+- **Memory usage**: Watch for leaks
+- **CPU profiler**: Identify bottlenecks