chore: Switch to production Firebase project

fix: Simplify icon to yellow star with transparent background

fix: Add proper ChatMarker star icon for all sizes

fix: Improve datetime picker and button styling in reminder modals

fix: Remove remote code URLs from Firebase Auth SDK for MV3 compliance

docs: Add comprehensive icon design guide for store submission

docs: Add complete privacy practices certification guide

fix: Correct host permission patterns in submission guide

deploy

feat: Add automatic cloud sync for all chat operations

fix: Make sync status function work in both popup and background contexts

docs: Make Firebase setup guide specific to ChatMarker

docs: Create unified Firebase setup guide for both extensions

docs: Update Firebase setup guide to match actual implementation

feat: Make scrollbars theme-aware for light and dark modes