feat(gateway): MosaicPlugin lifecycle + ReloadService + hot reload (P8-013) (#182)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/gateway/src/reload/reload.controller.ts

@@ -0,0 +1,22 @@
+import { Controller, HttpCode, HttpStatus, Inject, Post, UseGuards } from '@nestjs/common';
+import type { SystemReloadPayload } from '@mosaic/types';
+import { AdminGuard } from '../admin/admin.guard.js';
+import { ChatGateway } from '../chat/chat.gateway.js';
+import { ReloadService } from './reload.service.js';
+
+@Controller('api/admin')
+@UseGuards(AdminGuard)
+export class ReloadController {
+  constructor(
+    @Inject(ReloadService) private readonly reloadService: ReloadService,
+    @Inject(ChatGateway) private readonly chatGateway: ChatGateway,
+  ) {}
+
+  @Post('reload')
+  @HttpCode(HttpStatus.OK)
+  async triggerReload(): Promise<SystemReloadPayload> {
+    const result = await this.reloadService.reload('rest');
+    this.chatGateway.broadcastReload(result);
+    return result;
+  }
+}