implement event persistence and improve Mongoose TypeScript patterns

- Add event persistence: confirmed events are now saved to MongoDB
- Refactor Mongoose models to use virtuals for id field with IdVirtual interface
- Update repositories to use toJSON() with consistent type casting
- Add more test responses for chat (doctor, birthday, gym, etc.)
- Show event description in ProposedEventCard
- Change mongo-express port to 8083
- Update CLAUDE.md with Mongoose model pattern documentation

apps/server/src/repositories/mongo/MongoUserRepository.ts

@@ -1,29 +1,21 @@
 import { User } from '@caldav/shared';
 import { UserRepository, CreateUserData } from '../../services/interfaces';
-import { UserModel, UserDocument } from './models';
+import { UserModel } from './models';
 
 export class MongoUserRepository implements UserRepository {
-  private toUser(doc: UserDocument): User {
-    return {
-      id: doc._id.toString(),
-      email: doc.email,
-      displayName: doc.displayName,
-      createdAt: doc.createdAt,
-      updatedAt: doc.updatedAt,
-    };
-  }
-
   async findById(id: string): Promise<User | null> {
     throw new Error('Not implemented');
   }
 
   async findByEmail(email: string): Promise<User | null> {
     const user = await UserModel.findOne({ email: email.toLowerCase() });
-    return user ? this.toUser(user) : null;
+    // NOTE: Casting required because Mongoose's toJSON() type doesn't reflect our virtual 'id' field
+    return (user?.toJSON() as unknown as User) ?? null;
   }
 
   async create(data: CreateUserData): Promise<User> {
     const user = await UserModel.create(data);
-    return this.toUser(user);
+    // NOTE: Casting required because Mongoose's toJSON() type doesn't reflect our virtual 'id' field
+    return user.toJSON() as unknown as User;
   }
 }