feat: Gemini AI integration — conversations, messages, image gen

- Fixed YAML parse error (unquoted colon in description broke @scalar/json-magic)
- Converted orval.config.ts → orval.config.cjs (fixes orval v8 TypeScript config loading)
- Codegen now works: zod schemas + React Query hooks regenerated with Gemini types
- Added Gemini tag, 4 path groups, 8 schemas to openapi.yaml
- lib/integrations-gemini-ai wired: tsconfig refs, api-server package.json dep
- Created routes/gemini.ts: CRUD conversations/messages + SSE chat stream + image gen
- Mounted /gemini router in routes/index.ts

lib/api-spec/package.json

@@ -3,7 +3,7 @@
   "version": "0.0.0",
   "private": true,
   "scripts": {
-    "codegen": "orval --config ./orval.config.ts"
+    "codegen": "orval --config ./orval.config.cjs"
   },
   "devDependencies": {
     "orval": "^8.5.2"