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/models/EventModel.ts

@@ -1,9 +1,12 @@
-import mongoose, { Schema, Document } from 'mongoose';
+import mongoose, { Schema, Document, Model } from 'mongoose';
 import { CalendarEvent } from '@caldav/shared';
+import { IdVirtual } from './types';
 
-export interface EventDocument extends Omit<CalendarEvent, 'id'>, Document {}
+export interface EventDocument extends Omit<CalendarEvent, 'id'>, Document {
+  toJSON(): CalendarEvent;
+}
 
-const EventSchema = new Schema<EventDocument>(
+const EventSchema = new Schema<EventDocument, Model<EventDocument, {}, {}, IdVirtual>, {}, {}, IdVirtual>(
   {
     userId: {
       type: String,
@@ -40,9 +43,16 @@ const EventSchema = new Schema<EventDocument>(
   },
   {
     timestamps: true,
+    virtuals: {
+      id: {
+        get() {
+          return this._id.toString();
+        },
+      },
+    },
     toJSON: {
+      virtuals: true,
       transform: (_, ret: Record<string, unknown>) => {
-        ret.id = String(ret._id);
         delete ret._id;
         delete ret.__v;
         return ret;