ci: Auto-create release on version tag push

Change workflow trigger from manual release to tag push (v*).
Adds release job that creates Gitea release before building.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -1,12 +1,27 @@
 name: Build and Push
 
 on:
-  release:
+  push:
-    types: [published]
+    tags:
+      - 'v*'
 
 jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Create Gitea Release
+        uses: https://gitea.com/actions/release-action@main
+        with:
+          title: Release ${{ github.ref_name }}
+          body: "Automated release for ${{ github.ref_name }}"
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
   build:
     runs-on: ubuntu-latest
+    needs: release
     steps:
       - uses: actions/checkout@v4