Migrate to esbuild/Vitest and upgrade @actions/* to ESM-only versions (#492)

* Migrate build toolchain from ncc/Jest to esbuild/Vitest

Replace the legacy ncc/Jest/Babel build stack with a modern ESM toolchain:

Build:
- Replace @vercel/ncc with esbuild (--platform=node --target=node20 --format=esm)
- Add createRequire banner for CJS interop in ESM bundle
- Add "type": "module" to package.json
- Add tsc --noEmit typecheck script (esbuild strips types without checking)
- Add typecheck to husky pre-commit hook

Dependencies:
- Bump @actions/core@3, exec@3, io@3, tool-cache@4 (ESM-only)
- Replace jest/ts-jest/@babel/* with vitest@4

Tests:
- Convert 29 test files: jest.fn()→vi.fn(), jest.mock()→vi.mock(), jest.spyOn()→vi.spyOn()
- Fix vitest 4 compat: mockImplementation requires args, mock call tracking, await .rejects

CI:
- Update build step from ncc build → npm run build
- Update composite action to use npm run build

* Switch tsconfig to NodeNext module resolution

Change module/moduleResolution from ES2022/bundler to NodeNext/NodeNext
and target from ES2022 to ES2020.

- Add .js extensions to all relative imports across 59 source/test files
  (required by NodeNext module resolution)
- Add vitest/globals to tsconfig types array for global test API declarations

Author: davidgamero

.github/actions/minikube-setup/action.yml

@@ -15,18 +15,14 @@ runs:
            rm -rf node_modules/
            npm install
 
-      - name: Install ncc
+      - name: Build
         shell: bash
-        run: npm i -g @vercel/ncc
+        run: npm run build
 
       - name: Install conntrack
         shell: bash
         run: sudo apt-get install -y conntrack
 
-      - name: Build
-        shell: bash
-        run: ncc build src/run.ts -o lib
-
       - uses: Azure/setup-kubectl@776406bce94f63e41d621b960d78ee25c8b76ede # v4.0.1
         name: Install Kubectl
 

.github/workflows/run-integration-tests-private.yml

@@ -25,10 +25,10 @@ jobs:
            run: |
               rm -rf node_modules/
               npm install
-         - name: Install ncc
-           run: npm i -g @vercel/ncc
+
          - name: Build
-           run: ncc build src/run.ts -o lib
+           run: npm run build
+
          - name: Azure login
            uses: azure/[email protected]
            with:

.husky/pre-commit

@@ -1,3 +1,9 @@
+npm run typecheck || {
+  echo ""
+  echo "❌ Type check failed."
+  echo "💡 Run 'npm run typecheck' to see errors."
+  exit 1
+}
 npm test
 npm run format-check || {
   echo ""