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/01 - Architecture/Folder Structure.md

@@ -0,0 +1,54 @@
+# Folder Structure
+
+## Source Code (`lib/`)
+
+```
+lib/
+├── core/
+│   ├── analytics/          # Analytics integration
+│   ├── api/                # API client & interceptors
+│   ├── auth/               # Authentication logic
+│   ├── storage/            # Local storage implementations
+│   ├── utils/              # Utility functions
+│   ├── constants.dart      # App-wide constants
+│   └── theme_manager.dart  # Dark/Light mode state
+│
+├── features/
+│   ├── auth/               # Login, registration, session
+│   ├── events/             # Event listing, detail, creation
+│   ├── gamification/       # EP, RP, leaderboard, achievements
+│   └── reviews/            # Review system
+│
+├── screens/
+│   ├── home_screen.dart
+│   ├── home_desktop_screen.dart
+│   ├── login_screen.dart
+│   ├── desktop_login_screen.dart
+│   ├── booking_screen.dart
+│   ├── calendar_screen.dart
+│   ├── profile_screen.dart
+│   ├── search_screen.dart
+│   ├── responsive_layout.dart
+│   └── ...
+│
+├── widgets/                # Reusable UI components
+└── main.dart               # Entry point
+```
+
+## Platform Folders
+| Folder | Purpose |
+|--------|---------|
+| `android/` | Android native code |
+| `ios/` | iOS native code |
+| `web/` | Web entrypoint |
+| `macos/` | macOS native |
+| `windows/` | Windows native |
+| `linux/` | Linux native |
+
+## Assets
+```
+assets/
+├── images/
+├── fonts/
+└── videos/
+```