**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__/AssetService.test.ts

@@ -2,7 +2,7 @@ import { type Instance } from 'mobx-state-tree';
 import { renderPage } from 'vike/server';
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 
-import AssetService from '../services/AssetService.ts';
+import AssetService from '../src/services/AssetService.ts';
 
 // Define types for testing
 type AssetServiceInstance = Instance<typeof AssetService>;