feat(service): P2.4 REST fallback POST /v1/threads/:id/messages (session-auth)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/iios-service/src/threads/send-message.dto.ts

@@ -0,0 +1,6 @@
+import { IsOptional, IsString } from 'class-validator';
+
+export class SendMessageDto {
+  @IsString() content!: string;
+  @IsOptional() @IsString() contentRef?: string;
+}

packages/iios-service/src/threads/threads.controller.ts

@@ -1,12 +1,49 @@
-import { Controller, Get, Param } from '@nestjs/common';
+import { randomUUID } from 'node:crypto';
+import {
+  BadRequestException,
+  Body,
+  Controller,
+  Get,
+  Headers,
+  HttpCode,
+  Param,
+  Post,
+} from '@nestjs/common';
 import { ThreadsService } from './threads.service';
+import { MessageService } from '../messaging/message.service';
+import { SessionVerifier } from '../platform/session.verifier';
+import { SendMessageDto } from './send-message.dto';
 
 @Controller('v1/threads')
 export class ThreadsController {
-  constructor(private readonly threads: ThreadsService) {}
+  constructor(
+    private readonly threads: ThreadsService,
+    private readonly messages: MessageService,
+    private readonly session: SessionVerifier,
+  ) {}
 
   @Get(':id/messages')
-  async messages(@Param('id') id: string) {
+  async listMessages(@Param('id') id: string) {
     return this.threads.getMessages(id);
   }
+
+  /** REST/polling fallback for native send (same write as the socket path). */
+  @Post(':id/messages')
+  @HttpCode(201)
+  async send(
+    @Param('id') id: string,
+    @Body() body: SendMessageDto,
+    @Headers('authorization') authorization?: string,
+    @Headers('idempotency-key') idempotencyKey?: string,
+  ) {
+    const token = (authorization ?? '').replace(/^Bearer\s+/i, '');
+    if (!token) throw new BadRequestException('Authorization bearer token is required');
+    const principal = this.session.verify(token);
+    return this.messages.send(
+      id,
+      principal,
+      { content: body.content, contentRef: body.contentRef },
+      idempotencyKey ?? randomUUID(),
+    );
+  }
 }

packages/iios-service/src/threads/threads.module.ts

@@ -1,8 +1,10 @@
 import { Module } from '@nestjs/common';
 import { ThreadsController } from './threads.controller';
 import { ThreadsService } from './threads.service';
+import { MessageModule } from '../messaging/message.module';
 
 @Module({
+  imports: [MessageModule],
   controllers: [ThreadsController],
   providers: [ThreadsService],
   exports: [ThreadsService],