feat: add messaging, webhooks, Xero and QuickBooks integrations

backend/src/ Message/ Message-thread.entity.ts

@@ -0,0 +1,32 @@
+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  OneToMany,
+  CreateDateColumn,
+  Index,
+} from 'typeorm';
+import { Message } from './message.entity';
+
+@Entity('message_threads')
+@Index(['lastMessageAt'])
+export class MessageThread {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  /**
+   * JSON array of User UUIDs who are participants in this thread.
+   * Stored as JSONB for flexible multi-participant support.
+   */
+  @Column({ type: 'jsonb' })
+  participantIds: string[];
+
+  @Column({ type: 'timestamptz', nullable: true })
+  lastMessageAt: Date | null;
+
+  @CreateDateColumn({ type: 'timestamptz' })
+  createdAt: Date;
+
+  @OneToMany(() => Message, (msg) => msg.thread)
+  messages: Message[];
+}

backend/src/ Message/Message.entity.ts

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+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  ManyToOne,
+  JoinColumn,
+  CreateDateColumn,
+  Index,
+} from 'typeorm';
+import { MessageThread } from './message-thread.entity';
+import { User } from '../../../users/entities/user.entity';
+
+@Entity('messages')
+@Index(['threadId'])
+@Index(['senderUserId'])
+@Index(['isRead'])
+export class Message {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column({ type: 'uuid' })
+  threadId: string;
+
+  @ManyToOne(() => MessageThread, (thread) => thread.messages, { onDelete: 'CASCADE' })
+  @JoinColumn({ name: 'threadId' })
+  thread: MessageThread;
+
+  @Column({ type: 'uuid' })
+  senderUserId: string;
+
+  @ManyToOne(() => User, { onDelete: 'RESTRICT' })
+  @JoinColumn({ name: 'senderUserId' })
+  sender: User;
+
+  @Column({ type: 'text' })
+  body: string;
+
+  /**
+   * Tracks whether the message has been read.
+   * Note: in a multi-participant thread, this is a per-message global flag.
+   * For per-user read receipts, extend to a separate read_receipts table.
+   */
+  @Column({ type: 'boolean', default: false })
+  isRead: boolean;
+
+  @CreateDateColumn({ type: 'timestamptz' })
+  sentAt: Date;
+}

backend/src/ Message/Messaging.controller.ts

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+import {
+  Body,
+  Controller,
+  Get,
+  Param,
+  ParseUUIDPipe,
+  Patch,
+  Post,
+  Query,
+} from '@nestjs/common';
+import { MessagingService } from './messaging.service';
+import { CurrentUser } from '../auth/decorators/current.user.decorators';
+import { User } from '../users/entities/user.entity';
+import { CreateThreadDto, MessagePaginationDto, SendMessageDto } from './dto/messaging.dto';
+
+@Controller('messages')
+export class MessagingController {
+  constructor(private readonly messagingService: MessagingService) {}
+
+  /**
+   * POST /messages/threads
+   * Start a new thread with one or more participants.
+   */
+  @Post('threads')
+  createThread(@Body() dto: CreateThreadDto, @CurrentUser() user: User) {
+    return this.messagingService.createThread(dto, user.id);
+  }
+
+  /**
+   * GET /messages/threads
+   * List all threads for the current user, sorted by lastMessageAt desc.
+   */
+  @Get('threads')
+  listThreads(@CurrentUser() user: User) {
+    return this.messagingService.listThreads(user.id);
+  }
+
+  /**
+   * GET /messages/threads/:id/messages
+   * Paginated message history for a thread (participants only).
+   */
+  @Get('threads/:id/messages')
+  getMessages(
+    @Param('id', ParseUUIDPipe) threadId: string,
+    @CurrentUser() user: User,
+    @Query() pagination: MessagePaginationDto,
+  ) {
+    return this.messagingService.getThreadMessages(threadId, user.id, pagination);
+  }
+
+  /**
+   * POST /messages/threads/:id/messages
+   * Send a message to a thread; emits new-message WS event.
+   */
+  @Post('threads/:id/messages')
+  sendMessage(
+    @Param('id', ParseUUIDPipe) threadId: string,
+    @Body() dto: SendMessageDto,
+    @CurrentUser() user: User,
+  ) {
+    return this.messagingService.sendMessage(threadId, dto, user.id);
+  }
+
+  /**
+   * PATCH /messages/threads/:id/read
+   * Mark all unread messages in the thread as read.
+   */
+  @Patch('threads/:id/read')
+  markRead(
+    @Param('id', ParseUUIDPipe) threadId: string,
+    @CurrentUser() user: User,
+  ) {
+    return this.messagingService.markAsRead(threadId, user.id);
+  }
+
+  /**
+   * GET /messages/unread-count
+   * Returns the total unread message count for badge display.
+   */
+  @Get('unread-count')
+  unreadCount(@CurrentUser() user: User) {
+    return this.messagingService.getUnreadCount(user.id);
+  }
+}

backend/src/ Message/Messaging.dto.ts

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+import {
+  IsArray,
+  IsNotEmpty,
+  IsString,
+  IsUUID,
+  ArrayMinSize,
+} from 'class-validator';
+import { Type } from 'class-transformer';
+import { IsOptional, IsInt, Min, Max } from 'class-validator';
+
+// ── Create Thread ─────────────────────────────────────────────────────────
+
+export class CreateThreadDto {
+  @IsArray()
+  @ArrayMinSize(1, { message: 'At least one participant is required' })
+  @IsUUID('4', { each: true })
+  participantIds: string[];
+}
+
+// ── Send Message ──────────────────────────────────────────────────────────
+
+export class SendMessageDto {
+  @IsString()
+  @IsNotEmpty({ message: 'Message body cannot be empty' })
+  body: string;
+}
+
+// ── Paginate Messages ─────────────────────────────────────────────────────
+
+export class MessagePaginationDto {
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt()
+  @Min(1)
+  page?: number = 1;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt()
+  @Min(1)
+  @Max(100)
+  limit?: number = 20;
+}

backend/src/ Message/Messaging.module.ts

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+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { MessageThread } from './entities/message-thread.entity';
+import { Message } from './entities/message.entity';
+import { MessagingService } from './messaging.service';
+import { MessagingController } from './messaging.controller';
+import { NotificationsModule } from '../notifications/notifications.module';
+
+@Module({
+  imports: [
+    TypeOrmModule.forFeature([MessageThread, Message]),
+    NotificationsModule,   // provides NotificationsGateway for WS emit
+  ],
+  controllers: [MessagingController],
+  providers: [MessagingService],
+  exports: [MessagingService],
+})
+export class MessagingModule {}