**Refactor:** Restructure server package to streamline imports and improve file organization

- Moved `providers`, `services`, `models`, `lib`, and related files to `src` directory within `server` package.
- Adjusted imports across the codebase to reflect the new paths.
- Renamed several `.ts` files for consistency.
- Introduced an `index.ts` in the `ai/providers` package to export all providers.

This improves maintainability and aligns with the project's updated directory structure.

packages/server/__tests__/api-router.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect, vi } from 'vitest';
 
-import { createRouter } from '../api-router.ts';
+import { createRouter } from '../src/router/router.ts';
 
 // Mock the vike/server module
 vi.mock('vike/server', () => ({