ci: make validation compatible with Gitea runner

.github/workflows/ci.yml

@@ -13,17 +13,10 @@ jobs:
     name: Validate frontend and API
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-node@v7
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: 22
-          cache: npm
       - run: npm ci --include=dev
       - run: npm run typecheck
       - run: npm run build
-
-      - uses: actions/upload-artifact@v4
-        with:
-          name: frontend-build
-          path: dist
-          if-no-files-found: error

BACKEND.md

@@ -32,4 +32,4 @@ Public course endpoints return only public lessons and public assets. Enrolment
 
 ## CI/CD status
 
-GitHub Actions validates every pull request and every push to `main` by installing locked dependencies, type-checking the frontend and API, building the frontend, and uploading the production build as an artifact. Deployment remains intentionally unconfigured until the frontend and API hosting providers are chosen.
+Gitea Actions validates every pull request and every push to `main` by installing locked dependencies, type-checking the frontend and API, and building the frontend. The workflow deliberately does not upload a build artifact: the current Gitea runner does not support `upload-artifact@v4`, and Portainer builds the deployment image directly from the repository.