ci(release): add auto-merge PR and tag-on-main workflows

.github/scripts/extract-version.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+BRANCH="$1"
+VERSION="${BRANCH#release/v}"
+
+if ! echo "$VERSION" | grep -qE '^[0-9]+\.[0-9]+\.[0-9]+$'; then
+  echo "Invalid version format: $BRANCH (expected release/vX.Y.Z)" >&2
+  exit 1
+fi
+
+echo "$VERSION"

.github/workflows/release.yml

@@ -36,6 +36,8 @@ jobs:
     name: Pack and Publish
     runs-on: ubuntu-latest
     needs: test
+    outputs:
+      version: ${{ steps.version.outputs.value }}
     steps:
       - uses: actions/checkout@v6
         with:
@@ -44,12 +46,7 @@ jobs:
       - name: Extract version from branch name
         id: version
         run: |
-          BRANCH="${GITHUB_REF#refs/heads/}"
-          VERSION="${BRANCH#release/v}"
-          if ! echo "$VERSION" | grep -qE '^[0-9]+\.[0-9]+\.[0-9]+$'; then
-            echo "Invalid version format in branch name: $BRANCH (expected release/vX.Y.Z)"
-            exit 1
-          fi
+          VERSION=$(bash .github/scripts/extract-version.sh "${GITHUB_REF#refs/heads/}")
           echo "value=$VERSION" >> "$GITHUB_OUTPUT"
 
       - name: Setup .NET
@@ -74,3 +71,22 @@ jobs:
           --api-key ${{ secrets.NUGET_API_KEY }}
           --source https://api.nuget.org/v3/index.json
           --skip-duplicate
+
+  merge:
+    name: Open PR to Main
+    runs-on: ubuntu-latest
+    needs: publish
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Create PR and enable auto-merge
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          PR_URL=$(gh pr create \
+            --repo "$GITHUB_REPOSITORY" \
+            --title "Release v${{ needs.publish.outputs.version }}" \
+            --body "Automated release PR for v${{ needs.publish.outputs.version }}. Package published to NuGet successfully." \
+            --base main \
+            --head "${{ github.ref_name }}")
+          gh pr merge "$PR_URL" --merge --auto

.github/workflows/tag.yml

@@ -0,0 +1,33 @@
+name: Tag Release
+
+on:
+  pull_request:
+    types: [closed]
+    branches:
+      - main
+
+jobs:
+  tag:
+    name: Create Release Tag
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.merged == true && startsWith(github.event.pull_request.head.ref, 'release/')
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          ref: main
+          fetch-depth: 0
+
+      - name: Extract version from branch name
+        id: version
+        run: |
+          VERSION=$(bash .github/scripts/extract-version.sh "${{ github.event.pull_request.head.ref }}")
+          echo "value=$VERSION" >> "$GITHUB_OUTPUT"
+
+      - name: Create and push tag
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git tag "v${{ steps.version.outputs.value }}"
+          git push origin "v${{ steps.version.outputs.value }}"