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

tsconfig.json

@@ -12,6 +12,9 @@
     {
       "path": "./lib/integrations-anthropic-ai"
     },
+    {
+      "path": "./lib/integrations-gemini-ai"
+    },
     {
       "path": "./artifacts/api-server"
     }