feat: implement user profile page with statistics, contribution map, and activity timeline

- Add userService for profile and activity API calls
- Create UserProfilePage with tabbed interface (overview, reports, events, activity)
- Display user statistics (reports count, events count, impact score)
- Implement personal contribution map showing all user report locations
- Add activity timeline with different activity types
- Enable profile editing for own profile (first name, last name, username)
- Update UserProfile component to link to profile page
- Add /profile/:userId route to App
- Install react-leaflet for map integration
- Requirements: 6.3, 6.4, 6.5

package.json

@@ -19,6 +19,7 @@
     "leaflet.markercluster": "^1.5.3",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
+    "react-leaflet": "^5.0.0",
     "react-router-dom": "^7.9.6",
     "recharts": "^3.4.1"
   },