Add Gitea CI workflow

README.md

@@ -137,6 +137,27 @@ Optional environment variables:
 
 The script creates a disabled backup job and, by default, queues it once. Only run it when you intentionally want a real Proxmox backup and rclone upload.
 
+## CI
+
+Gitea Actions workflow:
+
+```text
+.gitea/workflows/ci.yml
+```
+
+It runs on pushes and pull requests to `main` and can also be started manually. The workflow checks:
+
+- backend dependency install and pytest;
+- frontend dependency install and production build;
+- shell script syntax.
+
+Package caches are enabled through the Gitea Actions cache-compatible setup actions:
+
+- Python/pip cache keyed by `backend/requirements.txt`;
+- npm cache keyed by `frontend/package-lock.json`.
+
+The Gitea runner must have action cache support configured for cache restore/save to work.
+
 ## Updates
 
 After pulling new code, apply it with: