ci: convert repository name to lowercase for Docker image tags

.cline-context.md

@@ -27,7 +27,7 @@
   - Configured production multi-stage `Dockerfile` with standalone Next.js runner, Prisma CLI migrations support, and automated `docker-entrypoint.sh` startup script.
   - Added `.dockerignore` for minimal context transfer and fast build times.
   - Refined `docker-compose.yml` and `.env.example` to support prebuilt registry images (`CHECKFLOW_IMAGE`) and automated database migrations.
-  - Automated Gitea Actions CI workflow (`.gitea/workflows/docker-build.yaml`) for building & pushing container images to Gitea Container Registry.
+  - Automated Gitea Actions CI workflow (`.gitea/workflows/docker-build.yaml`) for building & pushing container images to Gitea Container Registry with lowercase repository name normalization (`env.REPO`).
   - Completely revamped `README.md` to reflect project design philosophy, architecture, Docker setup, and open-standard CalDAV sync guidelines.
   - Validated that `npm run lint` and `npm run build` execute with 0 errors and 0 warnings.
 

.gitea/workflows/docker-build.yaml

@@ -14,6 +14,11 @@ jobs:
         with:
           token: ${{ secrets.CI_TOKEN }}
 
+      - name: Set lower case owner/repository
+        id: repo_name
+        run: |
+          echo "REPO=${GITHUB_REPOSITORY,,}" >> $GITHUB_ENV
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
@@ -29,4 +34,6 @@ jobs:
         with:
           context: .
           push: true
-          tags: ${{ secrets.DOCKER_REGISTRY || 'gitea.example.com' }}/${{ gitea.repository }}:latest
+          tags: |
+            ${{ secrets.DOCKER_REGISTRY || 'gitea.example.com' }}/${{ env.REPO }}:latest
+            ${{ secrets.DOCKER_REGISTRY || 'gitea.example.com' }}/${{ env.REPO }}:${{ gitea.sha }}