chore: remove vibe-coding artifacts from tracking, sync notes and obsidian config

- Untrack .claude/launch.json (Claude Code config)
- Add .claude/, .mcp.json, CLAUDE.md, and AI-generated CSVs to .gitignore
- Add _notes/ vault (architecture, API, tasks, bugs, infra docs)
- Add .obsidian/ plugin/vault config (workspace state excluded)
- Sync CHANGELOG.md

_notes/03 - Screens/Screen Index.md

@@ -0,0 +1,26 @@
+# Screen Index
+
+## Mobile Screens
+| Screen | File | Description |
+|--------|------|-------------|
+| Home | `lib/screens/home_screen.dart` | Main event feed |
+| Login | `lib/screens/login_screen.dart` | User login |
+| Booking | `lib/screens/booking_screen.dart` | Event booking flow |
+| Calendar | `lib/screens/calendar_screen.dart` | Calendar view |
+| Profile | `lib/screens/profile_screen.dart` | User profile & settings |
+| Search | `lib/screens/search_screen.dart` | Event search |
+
+## Desktop Screens
+| Screen | File | Description |
+|--------|------|-------------|
+| Home (Desktop) | `lib/screens/home_desktop_screen.dart` | Desktop dashboard |
+| Login (Desktop) | `lib/screens/desktop_login_screen.dart` | Desktop login |
+
+## Layout
+| File | Purpose |
+|------|---------|
+| `lib/screens/responsive_layout.dart` | Switches between mobile/desktop layouts |
+
+## Notes
+- Responsive layout builder detects screen width and renders the appropriate variant
+- Both mobile and desktop screens consume the same Providers