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

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

_notes/09 - Projects/Mobile - Flutter.md

@@ -0,0 +1,49 @@
+# Mobile App — Flutter
+
+**Platforms:** iOS, Android, Web, Desktop (Windows, macOS, Linux)
+**Local Path:** `/Users/bshtechnologies/Documents/Eventify-frontend/`
+**Version:** 1.6.1+17
+
+---
+
+## Tech Stack
+
+| Layer | Technology |
+|-------|-----------|
+| Framework | Flutter |
+| Language | Dart ^2.17.0 |
+| State Management | Provider 6.1.2 |
+| Maps | google_maps_flutter 2.5.0 |
+| Calendar | table_calendar 3.2.0 |
+| Location | geolocator 9.0.2 + geocoding 2.0.5 |
+| Media | image_picker, video_player |
+| Images | cached_network_image, flutter_svg |
+| Storage | shared_preferences |
+
+## Architecture
+
+Feature-first modular structure:
+```
+lib/
+├── core/          # API, auth, storage, utils, constants, theme
+├── features/      # auth, events, gamification, reviews
+├── screens/       # Mobile + desktop screen variants
+└── widgets/       # Reusable components
+```
+
+## Feature Modules
+- **Auth** — login, registration, session ([[02 - Features/Auth]])
+- **Events** — listing, detail, booking, calendar ([[02 - Features/Events]])
+- **Gamification** — EP, RP, leaderboard, achievements ([[02 - Features/Gamification]])
+- **Reviews** — event reviews ([[02 - Features/Reviews]])
+
+## Responsive Design
+- `responsive_layout.dart` switches between mobile and desktop layouts
+- Separate screen files for mobile vs desktop (e.g. `home_screen.dart` / `home_desktop_screen.dart`)
+
+## Notes
+
+## Related
+- [[01 - Architecture/Overview]]
+- [[03 - Screens/Screen Index]]
+- [[Backend - Django]]