Add documentation for geofence and locations features

- Add comprehensive geofence feature implementation plan
- Add locations documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

docs/locations.md

@@ -0,0 +1,84 @@
+# Location Database Documentation
+
+## Database File
+- **Filename:** `locations.sqlite`
+- **Type:** SQLite 3.x database
+- **Encoding:** UTF-8
+- **Current Records:** 367 location entries
+
+## Database Schema
+
+### Location Table
+
+| Column | Type | Required | Default | Description |
+|--------|------|----------|---------|-------------|
+| `id` | INTEGER | - | AUTO_INCREMENT | Primary key |
+| `latitude` | REAL | Yes | - | GPS latitude coordinate |
+| `longitude` | REAL | Yes | - | GPS longitude coordinate |
+| `timestamp` | TEXT | Yes | - | Time when location was recorded |
+| `user_id` | INTEGER | No | 0 | Telegram user ID |
+| `first_name` | TEXT | No | - | User's first name |
+| `last_name` | TEXT | No | - | User's last name |
+| `username` | TEXT | No | - | Telegram username |
+| `marker_label` | TEXT | No | - | Custom label for map marker |
+| `display_time` | TEXT | No | - | Formatted time for display |
+| `chat_id` | INTEGER | No | 0 | Telegram chat ID |
+| `battery` | INTEGER | No | - | Device battery level (0-100) |
+| `speed` | REAL | No | - | Movement speed |
+| `created_at` | TEXT | No | datetime('now') | Database insertion timestamp |
+
+## Database Tables
+- `Location` - Main table storing location data
+- `sqlite_sequence` - SQLite internal table for auto-increment tracking
+
+## Verification Commands
+
+### Check database file
+```bash
+file locations.sqlite
+```
+
+### List all tables
+```bash
+sqlite3 locations.sqlite "SELECT name FROM sqlite_master WHERE type='table';"
+```
+
+### View table schema
+```bash
+sqlite3 locations.sqlite "PRAGMA table_info(Location);"
+```
+
+### Count records
+```bash
+sqlite3 locations.sqlite "SELECT COUNT(*) FROM Location;"
+```
+
+### Sample query
+```bash
+sqlite3 locations.sqlite "SELECT id, latitude, longitude, timestamp, user_id FROM Location LIMIT 5;"
+```
+
+## Future Development Ideas
+
+### Potential Features
+- [ ] Location history visualization
+- [ ] Geofencing alerts
+- [ ] Route tracking and analysis
+- [ ] Speed monitoring and statistics
+- [ ] Battery level tracking over time
+- [ ] Multi-user location comparison
+- [ ] Export to GPX/KML formats
+- [ ] Privacy controls and data retention policies
+
+### Optimization Opportunities
+- [ ] Add indexes on frequently queried columns (user_id, timestamp)
+- [ ] Implement data archival for old records
+- [ ] Add spatial queries support (SQLite R*Tree extension)
+- [ ] Implement location clustering for map display
+
+### Integration Points
+- [ ] REST API for location queries
+- [ ] Real-time location updates via WebSocket/MQTT
+- [ ] Map visualization frontend
+- [ ] Mobile app data sync
+- [ ] Export/backup functionality