extend chat model with CRUD actions for event changes

- Add ProposedEventChange type with create/update/delete actions
- Replace proposedEvent with proposedChange in ChatMessage
- Add currentDate to AIContext for time-aware AI responses
- Add AI test endpoint for development (/api/ai/test)
- Fix MongoUserRepository type safety with explicit toUser mapping
- Update CLAUDE.md documentation

apps/server/src/repositories/mongo/models/ChatModel.ts

@@ -1,10 +1,10 @@
 import mongoose, { Schema, Document } from 'mongoose';
-import { ChatMessage, Conversation, CreateEventDTO } from '@caldav/shared';
+import { ChatMessage, Conversation, CreateEventDTO, UpdateEventDTO, ProposedEventChange } from '@caldav/shared';
 
 export interface ChatMessageDocument extends Omit<ChatMessage, 'id'>, Document {}
 export interface ConversationDocument extends Omit<Conversation, 'id'>, Document {}
 
-const ProposedEventSchema = new Schema<CreateEventDTO>(
+const EventSchema = new Schema<CreateEventDTO>(
   {
     title: { type: String, required: true },
     description: { type: String },
@@ -17,6 +17,29 @@ const ProposedEventSchema = new Schema<CreateEventDTO>(
   { _id: false }
 );
 
+const UpdatesSchema = new Schema<UpdateEventDTO>(
+  {
+    title: { type: String },
+    description: { type: String },
+    startTime: { type: Date },
+    endTime: { type: Date },
+    note: { type: String },
+    isRecurring: { type: Boolean },
+    recurrenceRule: { type: String },
+  },
+  { _id: false }
+);
+
+const ProposedChangeSchema = new Schema<ProposedEventChange>(
+  {
+    action: { type: String, enum: ['create', 'update', 'delete'], required: true },
+    eventId: { type: String },
+    event: { type: EventSchema },
+    updates: { type: UpdatesSchema },
+  },
+  { _id: false }
+);
+
 const ChatMessageSchema = new Schema<ChatMessageDocument>(
   {
     conversationId: {
@@ -32,8 +55,8 @@ const ChatMessageSchema = new Schema<ChatMessageDocument>(
       type: String,
       required: true,
     },
-    proposedEvent: {
-      type: ProposedEventSchema,
+    proposedChange: {
+      type: ProposedChangeSchema,
     },
   },
   {