ci: support curated release notes via RELEASE_NOTES.md (#134)

Add two steps to the release workflow:

1. Override: if RELEASE_NOTES.md exists on the tagged commit, replace the
   GitHub Release body with its contents via gh release edit.
2. Cleanup: after the release, create a PR to delete RELEASE_NOTES.md
   from main using a GitHub App token (so the PR triggers CI/auto-approve).

When no RELEASE_NOTES.md is present, behavior is unchanged (release-please
auto-generated notes are used as before).

Signed-off-by: Sebastien Tardif <sebtardif@ncf.ca>

Author: SebTardif

.github/workflows/release.yml

@@ -71,6 +71,16 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: gh release upload "${{ needs.release-please.outputs.tag_name }}" patchloom.vsix
+      - name: Apply custom release notes
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          if [ -f RELEASE_NOTES.md ]; then
+            echo "Custom release notes found, updating release body..."
+            gh release edit "${{ needs.release-please.outputs.tag_name }}" --notes-file RELEASE_NOTES.md
+          else
+            echo "No custom release notes, using auto-generated notes"
+          fi
       # See ~/.grok/skills/vsce-publish/SKILL.md (or /vsce-publish) for the full
       # one-time browser setup (aex.dev.azure.com, PAT scopes, Open VSX agreement
       # + create-namespace + ownership claim), secret names, and troubleshooting.
@@ -97,3 +107,34 @@ jobs:
           color: blue
           namedLogo: visualstudiocode
           logoColor: white
+      # Clean up RELEASE_NOTES.md after release (uses App token so the PR triggers CI/auto-approve)
+      - uses: actions/create-github-app-token@bcd2ba49218906704ab6c1aa796996da409d3eb1 # v3.2.0
+        if: hashFiles('RELEASE_NOTES.md') != ''
+        id: cleanup-token
+        with:
+          client-id: ${{ vars.APP_CLIENT_ID }}
+          private-key: ${{ secrets.APP_PRIVATE_KEY }}
+      - name: Clean up release notes file
+        if: steps.cleanup-token.outcome == 'success'
+        env:
+          GH_TOKEN: ${{ steps.cleanup-token.outputs.token }}
+        run: |
+          if git ls-tree HEAD --name-only | grep -q '^RELEASE_NOTES.md$'; then
+            TAG="${{ needs.release-please.outputs.tag_name }}"
+            BRANCH="chore/cleanup-release-notes-${TAG}"
+            gh api "repos/${{ github.repository }}/git/refs" \
+              -f ref="refs/heads/$BRANCH" \
+              -f sha="$(git rev-parse HEAD)"
+            FILE_SHA=$(gh api \
+              "repos/${{ github.repository }}/contents/RELEASE_NOTES.md?ref=$BRANCH" \
+              --jq '.sha')
+            gh api --method DELETE \
+              "repos/${{ github.repository }}/contents/RELEASE_NOTES.md" \
+              -f message="chore: remove release notes override" \
+              -f sha="$FILE_SHA" \
+              -f branch="$BRANCH"
+            PR_URL=$(gh pr create --base main --head "$BRANCH" \
+              --title "chore: remove release notes override" \
+              --body "Auto-cleanup after ${TAG} release.")
+            gh pr merge "$PR_URL" --auto --squash
+          fi