Implement notification preferences (Task 16)

- Create NotificationSettings component with map-based area selector
- Add radius configuration slider (1-50km range)
- Implement notification type toggles (email, in-app)
- Add notifications tab to user profile page (visible only to profile owner)
- Update backend to parse and return areasOfInterest JSON
- Save and load user notification preferences
- Requirements: 10.1, 10.4

server/src/services/userService.ts

@@ -98,8 +98,21 @@ export class UserService {
       throw new Error('User not found');
     }
 
+    // Parse areasOfInterest from JSON string if it exists
+    let areasOfInterest = [];
+    if (user.areasOfInterest) {
+      try {
+        areasOfInterest = typeof user.areasOfInterest === 'string' 
+          ? JSON.parse(user.areasOfInterest) 
+          : user.areasOfInterest;
+      } catch (e) {
+        console.error('Error parsing areasOfInterest:', e);
+      }
+    }
+
     return {
       ...user,
+      areasOfInterest,
       reportCount: user._count.reports,
       eventCount: user._count.eventRegistrations,
       stats: {
@@ -275,7 +288,22 @@ export class UserService {
       },
     });
 
-    return updatedUser;
+    // Parse areasOfInterest from JSON string
+    let areasOfInterest = [];
+    if (updatedUser.areasOfInterest) {
+      try {
+        areasOfInterest = typeof updatedUser.areasOfInterest === 'string' 
+          ? JSON.parse(updatedUser.areasOfInterest) 
+          : updatedUser.areasOfInterest;
+      } catch (e) {
+        console.error('Error parsing areasOfInterest:', e);
+      }
+    }
+
+    return {
+      ...updatedUser,
+      areasOfInterest,
+    };
   }
 
   /**