fix: remove RELEASE_NOTES.md from repo and add to .gitignore (#37)

RELEASE_NOTES.md is a temporary file generated during the release
workflow for goreleaser to consume. It should not be tracked in git.

Author: hi-lei

.github/workflows/release.yml

@@ -58,7 +58,7 @@ jobs:
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
           git remote set-url origin https://x-access-token:${{ secrets.RELEASE_TOKEN }}@github.com/${{ github.repository }}
-          git add CHANGELOG.md RELEASE_NOTES.md
+          git add CHANGELOG.md
           git commit -m "chore(release): update changelog for ${VERSION}"
           git tag "${VERSION}"
           git push origin main --tags
@@ -150,6 +150,3 @@ jobs:
             "dist/verda_${VER}_binary_SHA256SUMS.pem" \
             "dist/verda_${VER}_SHA256SUMS.sig" \
             "dist/verda_${VER}_SHA256SUMS.pem"
-
-      - name: Clean up release notes
-        run: rm -f RELEASE_NOTES.md

.gitignore

@@ -376,6 +376,9 @@ scripts/live-test.sh
 .claude/commands/
 .claude/topic-switch.json
 
+# Release artifacts (generated during CI release workflow)
+RELEASE_NOTES.md
+
 # AI working notes and implementation plans (not shipped)
 .ai/notes/
 docs/plans/