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/coord/coord.controller.ts

@@ -8,12 +8,30 @@ import {
   Query,
   UseGuards,
 } from '@nestjs/common';
+import fs from 'node:fs';
 import path from 'node:path';
 import { AuthGuard } from '../auth/auth.guard.js';
 import { CoordService } from './coord.service.js';
 
+/** Walk up from cwd to find the monorepo root (has pnpm-workspace.yaml). */
+function findMonorepoRoot(start: string): string {
+  let dir = start;
+  for (let i = 0; i < 5; i++) {
+    try {
+      fs.accessSync(path.join(dir, 'pnpm-workspace.yaml'));
+      return dir;
+    } catch {
+      const parent = path.dirname(dir);
+      if (parent === dir) break;
+      dir = parent;
+    }
+  }
+  return start;
+}
+
 /** Only paths under these roots are allowed for coord queries. */
-const ALLOWED_ROOTS = [process.cwd()];
+const WORKSPACE_ROOT = process.env['MOSAIC_WORKSPACE_ROOT'] ?? findMonorepoRoot(process.cwd());
+const ALLOWED_ROOTS = [process.cwd(), WORKSPACE_ROOT];
 
 function resolveAndValidatePath(raw: string | undefined): string {
   const resolved = path.resolve(raw ?? process.cwd());