fix: add missing @objectstack/service-ai dependency to studio package.json

Agent-Logs-Url: https://github.com/objectstack-ai/spec/sessions/e82878dc-90a9-435c-a7c4-9746c06d05e1

Co-authored-by: xuyushun441-sys <255036401+xuyushun441-sys@users.noreply.github.com>

Author: Copilot

apps/studio/package.json

@@ -31,6 +31,7 @@
     "@objectstack/plugin-msw": "workspace:*",
     "@objectstack/plugin-security": "workspace:*",
     "@objectstack/runtime": "workspace:*",
+    "@objectstack/service-ai": "workspace:*",
     "@objectstack/service-feed": "workspace:*",
     "@objectstack/spec": "workspace:*",
     "@radix-ui/react-avatar": "^1.1.11",