feat(releaseprep): migrate standalone tool into vociferate

.gitea/workflows/prepare-release.yml

@@ -0,0 +1,83 @@
+name: Prepare Release
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: Semantic version to release, with or without leading v.
+        required: true
+
+jobs:
+  prepare:
+    runs-on: ubuntu-latest
+    container: docker.io/catthehacker/ubuntu:act-latest
+    defaults:
+      run:
+        shell: bash
+    env:
+      RELEASE_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.26.1'
+          check-latest: true
+          cache: true
+          cache-dependency-path: go.sum
+
+      - name: Prepare release files
+        env:
+          RELEASE_VERSION: ${{ inputs.version }}
+        run: |
+          set -euo pipefail
+          ./script/prepare-release.sh "$RELEASE_VERSION"
+
+      - name: Run tests
+        run: |
+          set -euo pipefail
+          go test ./...
+
+      - name: Configure git author
+        run: |
+          set -euo pipefail
+          git config user.name "gitea-actions[bot]"
+          git config user.email "gitea-actions[bot]@users.noreply.local"
+
+      - name: Commit release changes and push tag
+        env:
+          RELEASE_VERSION: ${{ inputs.version }}
+        run: |
+          set -euo pipefail
+
+          normalized_version="${RELEASE_VERSION#v}"
+          tag="v${normalized_version}"
+
+          if git rev-parse "$tag" >/dev/null 2>&1; then
+            echo "Tag ${tag} already exists" >&2
+            exit 1
+          fi
+
+          case "$GITHUB_SERVER_URL" in
+            https://*)
+              authed_remote="https://oauth2:${RELEASE_TOKEN}@${GITHUB_SERVER_URL#https://}/${GITHUB_REPOSITORY}.git"
+              ;;
+            http://*)
+              authed_remote="http://oauth2:${RELEASE_TOKEN}@${GITHUB_SERVER_URL#http://}/${GITHUB_REPOSITORY}.git"
+              ;;
+            *)
+              echo "Unsupported GITHUB_SERVER_URL: ${GITHUB_SERVER_URL}" >&2
+              exit 1
+              ;;
+          esac
+
+          git remote set-url origin "$authed_remote"
+          git add changelog.md internal/releaseprep/version/version.go
+          git commit -m "release: prepare ${tag}"
+          git tag "$tag"
+          git push origin HEAD
+          git push origin "$tag"