Better GitHub releases, CalDav and Google Calendar improvements

🌟 New & Improved

• PR checks added to keep your code shining!
  Automatic build & test checks run on every pull request to keep quality high. 🛡️
  (via .github/workflows/pr-check.yml)

• Release notes with emoji flavor:
  Switched from .releaserc.json to a custom .releaserc.js.
  Now your release notes get fun emoji summaries and contributor callouts! 🎉

📅 Calendar Sync Enhancements

• Google & CalDAV calendar sync, made smarter:
  • Default to syncing one week if no date range is specified, making background syncing more user-friendly. 📆
  • More accurate logic for date ranges and event deletion — no unexpected overreach! ✨

🛠️ Refactors & Cleanups

• Streamlined API logic in calendar sync endpoints for better reliability and future improvements.

Have a good day!