fix(agent-service): add @types/multer to devDependencies

Fixes TS2307 build error: Cannot find module 'multer' or its type declarations.

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

packages/services/agent-service/package.json

@@ -38,6 +38,7 @@
     "@types/express": "^4.17.21",
     "@types/glob": "^8.1.0",
     "@types/jest": "^29.5.0",
+    "@types/multer": "^1.4.11",
     "@types/ws": "^8.5.0",
     "@types/node": "^20.11.0",
     "jest": "^29.7.0",

pnpm-lock.yaml

@@ -99,6 +99,9 @@ importers:
       '@types/jest':
         specifier: ^29.5.0
         version: 29.5.14
+      '@types/multer':
+        specifier: ^1.4.11
+        version: 1.4.13
       '@types/node':
         specifier: ^20.11.0
         version: 20.19.33