fix: add missing @Inject() decorators and fix coord workspace root detection

- Add @Inject() to all gateway constructor params (required without emitDecoratorMetadata)
  - AgentService: ProviderService, CoordService
  - RoutingService: ProviderService
  - ProvidersController: ProviderService, RoutingService
  - SessionsController: AgentService
- Fix coord controller ALLOWED_ROOTS to walk up to monorepo root (pnpm-workspace.yaml)
- Gateway now boots and serves all routes correctly

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/gateway/src/agent/sessions.controller.ts

@@ -4,6 +4,7 @@ import {
   Get,
   HttpCode,
   HttpStatus,
+  Inject,
   NotFoundException,
   Param,
   UseGuards,
@@ -14,7 +15,7 @@ import { AgentService } from './agent.service.js';
 @Controller('api/sessions')
 @UseGuards(AuthGuard)
 export class SessionsController {
-  constructor(private readonly agentService: AgentService) {}
+  constructor(@Inject(AgentService) private readonly agentService: AgentService) {}
 
   @Get()
   list() {