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/integrations-gemini-ai/src/client.ts

@@ -0,0 +1,21 @@
+import { GoogleGenAI } from "@google/genai";
+
+if (!process.env.AI_INTEGRATIONS_GEMINI_BASE_URL) {
+  throw new Error(
+    "AI_INTEGRATIONS_GEMINI_BASE_URL must be set. Did you forget to provision the Gemini AI integration?",
+  );
+}
+
+if (!process.env.AI_INTEGRATIONS_GEMINI_API_KEY) {
+  throw new Error(
+    "AI_INTEGRATIONS_GEMINI_API_KEY must be set. Did you forget to provision the Gemini AI integration?",
+  );
+}
+
+export const ai = new GoogleGenAI({
+  apiKey: process.env.AI_INTEGRATIONS_GEMINI_API_KEY,
+  httpOptions: {
+    apiVersion: "",
+    baseUrl: process.env.AI_INTEGRATIONS_GEMINI_BASE_URL,
+  },
+});