feat: migrate to ESM, add test suite and CI workflow

Convert the project to use proper ES modules with modern best practices:
- Add "type": "module" to package.json for native ESM support
- Replace CommonJS entry point check with ESM-compatible import.meta.url
- Update main entry point to dist/index.js

Add comprehensive test coverage:
- Implement integration test suite with Vitest
- Test documentation download, caching, and search functionality
- Add security tests for path traversal protection
- Test resource URI handling and error cases
- All 9 tests passing

Set up continuous integration:
- Add GitHub Actions CI workflow for automated testing
- Run type checking and test suite on all commits and PRs
- Use Node.js 20.x for consistent build environment

Other improvements:
- Add resources/docs.ts to modularize resource handling
- Export server and main function for better testability
- Remove obsolete test_server.manual.ts file
- Update dependencies including Vitest 4.0.15

Author: GhostTypes

.github/workflows/ci.yml

@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run type check
+        run: npm run build
+
+      - name: Run tests
+        run: npm test