feat: complete tRPC integration and fix platform UI issues

- Implement comprehensive tRPC setup with type-safe API
- Create tRPC routers for dashboard, admin, and auth endpoints
- Migrate frontend components to use tRPC client
- Fix platform dashboard Settings button functionality
- Add platform settings page with profile and security management
- Create OpenAI API mocking infrastructure for cost-safe testing
- Update tests to work with new tRPC architecture
- Sync database schema to fix AIBatchRequest table errors

tests/api/dashboard-metrics.test.ts

@@ -340,4 +340,4 @@ describe("/api/dashboard/metrics", () => {
       expect(data.error).toBe("Internal server error");
     });
   });
-});
+});