ci: switch release workflow to tag-driven

Trigger on `push: tags` instead of `workflow_dispatch`. The pushed tag
name is the version — removes the bump-input + compute-and-create-tag
dance, avoiding accidental major bumps from the manual dispatch form.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -1,17 +1,9 @@
 name: Release
 
 on:
-  workflow_dispatch:
-    inputs:
-      bump:
-        description: "Version bump type"
-        required: true
-        default: "patch"
-        type: choice
-        options:
-          - patch
-          - minor
-          - major
+  push:
+    tags:
+      - 'v*'
 
 jobs:
   ci:
@@ -45,25 +37,17 @@ jobs:
           cd repo
           git checkout ${{ gitea.ref_name }}
 
-      - name: Compute version
+      - name: Resolve version from tag
         working-directory: repo
         run: |
-          LATEST_TAG=$(git tag -l 'v*' --sort=-v:refname | head -n1)
-          if [ -z "$LATEST_TAG" ]; then
-            LATEST_TAG="v0.0.0"
+          VERSION="${{ gitea.ref_name }}"
+          PREV_TAG=$(git tag -l 'v*' --sort=-v:refname | grep -vxF "$VERSION" | head -n1)
+          if [ -z "$PREV_TAG" ]; then
+            PREV_TAG="v0.0.0"
           fi
-          MAJOR=$(echo "$LATEST_TAG" | sed 's/v//' | cut -d. -f1)
-          MINOR=$(echo "$LATEST_TAG" | sed 's/v//' | cut -d. -f2)
-          PATCH=$(echo "$LATEST_TAG" | sed 's/v//' | cut -d. -f3)
-          case "${{ gitea.event.inputs.bump }}" in
-            major) MAJOR=$((MAJOR+1)); MINOR=0; PATCH=0 ;;
-            minor) MINOR=$((MINOR+1)); PATCH=0 ;;
-            patch) PATCH=$((PATCH+1)) ;;
-          esac
-          NEW_VERSION="v${MAJOR}.${MINOR}.${PATCH}"
-          echo "VERSION=$NEW_VERSION" >> "$GITHUB_ENV"
-          echo "PREV_TAG=$LATEST_TAG" >> "$GITHUB_ENV"
-          echo "New version: $NEW_VERSION"
+          echo "VERSION=$VERSION" >> "$GITHUB_ENV"
+          echo "PREV_TAG=$PREV_TAG" >> "$GITHUB_ENV"
+          echo "Releasing $VERSION (previous: $PREV_TAG)"
 
       - name: Generate changelog
         working-directory: repo
@@ -77,14 +61,6 @@ jobs:
           echo "$CHANGELOG" >> "$GITHUB_ENV"
           echo "CHANGELOG_EOF" >> "$GITHUB_ENV"
 
-      - name: Create and push tag
-        working-directory: repo
-        run: |
-          git config user.name "Gitea Actions"
-          git config user.email "actions@gitea.jeanlucmakiola.de"
-          git tag -a "$VERSION" -m "Release $VERSION"
-          git push origin "$VERSION"
-
       - name: Build and push Docker image
         working-directory: repo
         run: |