feat: add automated release workflow for module tags

Adds a GitHub Actions workflow that automatically creates releases when module tags are pushed.

Features:
- Triggers on release/<namespace>/<module>/v*.*.* tag pattern
- Generates changelog filtered to only show changes for the specific module
- Extracts PR numbers and GitHub usernames from commit messages
- Creates GitHub release with proper title and changelog

Example: pushing 'release/coder-labs/sourcegraph-amp/v1.0.1' will create a release
with changelog showing only changes to the sourcegraph-amp module.

Co-authored-by: matifali <[email protected]>

Author: blink-so[bot]

.github/workflows/release.yml

@@ -0,0 +1,135 @@
+name: Create Release
+
+on:
+  push:
+    tags:
+      # Matches release/<namespace>/<resource_name>/<semantic_version>
+      # (e.g., "release/coder-labs/sourcegraph-amp/v1.0.1")
+      - "release/*/*/v*.*.*"
+
+jobs:
+  create-release:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: read
+    
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # Fetch full history for changelog generation
+      
+      - name: Extract tag information
+        id: tag_info
+        run: |
+          TAG=${GITHUB_REF#refs/tags/}
+          echo "tag=$TAG" >> $GITHUB_OUTPUT
+          
+          # Extract namespace, module, and version from tag
+          # Format: release/namespace/module/version
+          IFS='/' read -ra PARTS <<< "$TAG"
+          NAMESPACE="${PARTS[1]}"
+          MODULE="${PARTS[2]}"
+          VERSION="${PARTS[3]}"
+          
+          echo "namespace=$NAMESPACE" >> $GITHUB_OUTPUT
+          echo "module=$MODULE" >> $GITHUB_OUTPUT
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+          echo "module_path=registry/$NAMESPACE/modules/$MODULE" >> $GITHUB_OUTPUT
+          
+          # Create release title
+          RELEASE_TITLE="$NAMESPACE/$MODULE $VERSION"
+          echo "release_title=$RELEASE_TITLE" >> $GITHUB_OUTPUT
+      
+      - name: Find previous tag
+        id: prev_tag
+        run: |
+          NAMESPACE="${{ steps.tag_info.outputs.namespace }}"
+          MODULE="${{ steps.tag_info.outputs.module }}"
+          CURRENT_TAG="${{ steps.tag_info.outputs.tag }}"
+          
+          # Find the previous tag for this specific module
+          PREV_TAG=$(git tag -l "release/$NAMESPACE/$MODULE/v*" | grep -v "$CURRENT_TAG" | sort -V | tail -1)
+          
+          if [ -z "$PREV_TAG" ]; then
+            echo "No previous tag found, using initial commit"
+            PREV_TAG=$(git rev-list --max-parents=0 HEAD)
+          fi
+          
+          echo "prev_tag=$PREV_TAG" >> $GITHUB_OUTPUT
+          echo "Previous tag: $PREV_TAG"
+      
+      - name: Generate changelog
+        id: changelog
+        run: |
+          NAMESPACE="${{ steps.tag_info.outputs.namespace }}"
+          MODULE="${{ steps.tag_info.outputs.module }}"
+          MODULE_PATH="${{ steps.tag_info.outputs.module_path }}"
+          PREV_TAG="${{ steps.prev_tag.outputs.prev_tag }}"
+          CURRENT_TAG="${{ steps.tag_info.outputs.tag }}"
+          
+          echo "Generating changelog for $MODULE_PATH between $PREV_TAG and $CURRENT_TAG"
+          
+          # Get commits that affected the specific module path
+          COMMITS=$(git log --oneline --no-merges "$PREV_TAG..$CURRENT_TAG" -- "$MODULE_PATH" | cut -d' ' -f1)
+          
+          if [ -z "$COMMITS" ]; then
+            echo "No commits found for this module"
+            echo "changelog=No changes found for this module." >> $GITHUB_OUTPUT
+            exit 0
+          fi
+          
+          # Generate changelog from commits
+          CHANGELOG="## What's Changed\n\n"
+          
+          for commit in $COMMITS; do
+            # Get commit message
+            COMMIT_MSG=$(git log --format="%s" -n 1 $commit)
+            
+            # Extract PR number from commit message (handles various formats)
+            PR_NUM=$(echo "$COMMIT_MSG" | grep -oE '\(#[0-9]+\)|#[0-9]+' | grep -oE '[0-9]+' | head -1 || echo "")
+            
+            # Get GitHub username from commit (try multiple methods)
+            # First try to get from commit trailer
+            GH_USER=$(git log --format="%(trailers:key=Co-authored-by,valueonly)" -n 1 $commit | head -1 | grep -oE '@[^>]+' | cut -d'@' -f2 | cut -d'.' -f1 || echo "")
+            
+            # If no co-author, try to extract from email
+            if [ -z "$GH_USER" ]; then
+              EMAIL=$(git log --format="%ae" -n 1 $commit)
+              if [[ "$EMAIL" == *"@users.noreply.github.com" ]]; then
+                GH_USER=$(echo "$EMAIL" | cut -d'@' -f1 | sed 's/^[0-9]*+//')
+              else
+                GH_USER=$(echo "$EMAIL" | cut -d'@' -f1)
+              fi
+            fi
+            
+            # Fallback to commit author name if no GitHub username found
+            if [ -z "$GH_USER" ]; then
+              GH_USER=$(git log --format="%an" -n 1 $commit | tr ' ' '-' | tr '[:upper:]' '[:lower:]')
+            fi
+            
+            # Format changelog entry
+            if [ -n "$PR_NUM" ]; then
+              CHANGELOG="${CHANGELOG}* $COMMIT_MSG by @$GH_USER in https://github.com/coder/registry/pull/$PR_NUM\n"
+            else
+              CHANGELOG="${CHANGELOG}* $COMMIT_MSG by @$GH_USER\n"
+            fi
+          done
+          
+          # Add full changelog link
+          CHANGELOG="${CHANGELOG}\n\n**Full Changelog**: https://github.com/coder/registry/compare/$PREV_TAG...$CURRENT_TAG"
+          
+          # Save changelog to output (escape newlines for GitHub Actions)
+          echo "changelog<<EOF" >> $GITHUB_OUTPUT
+          echo -e "$CHANGELOG" >> $GITHUB_OUTPUT
+          echo "EOF" >> $GITHUB_OUTPUT
+      
+      - name: Create Release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh release create "${{ steps.tag_info.outputs.tag }}" \
+            --title "${{ steps.tag_info.outputs.release_title }}" \
+            --notes "${{ steps.changelog.outputs.changelog }}" \
+            --latest