Fix release workflow tag reference

- Use gitea.ref_name directly for tag
- Hardcode username as sansan
- Remove version extraction step

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

.gitea/workflows/release.yaml

@@ -26,17 +26,9 @@ jobs:
         uses: docker/login-action@v3
         with:
           registry: gitea.sanplex.xyz
-          username: ${{ gitea.repository_owner }}
+          username: sansan
           password: ${{ secrets.TOKEN }}
 
-      - name: Extract version from tag
-        id: meta
-        run: |
-          TAG=${GITEA_REF#refs/tags/}
-          VERSION=${TAG#v}
-          echo "TAG=$TAG" >> $GITHUB_OUTPUT
-          echo "VERSION=$VERSION" >> $GITHUB_OUTPUT
-
       - name: Build and push multi-arch image
         uses: docker/build-push-action@v5
         with:
@@ -45,8 +37,7 @@ jobs:
           platforms: linux/amd64,linux/arm64
           push: true
           tags: |
-            gitea.sanplex.xyz/sansan/musicfrontend:${{ steps.meta.outputs.VERSION }}
-            gitea.sanplex.xyz/sansan/musicfrontend:${{ steps.meta.outputs.TAG }}
+            gitea.sanplex.xyz/sansan/musicfrontend:${{ gitea.ref_name }}
             gitea.sanplex.xyz/sansan/musicfrontend:latest
           cache-from: type=gha
           cache-to: type=gha,mode=max