Implement complete bookmark functionality for Bible reading

Add both chapter-level and verse-level bookmarking capabilities:

Database Changes:
- Add ChapterBookmark table for chapter-level bookmarks
- Update schema with proper relationships to User and BibleBook models
- Maintain existing Bookmark table for verse-level bookmarks

API Endpoints:
- /api/bookmarks/chapter (GET, POST, DELETE) with check endpoint
- /api/bookmarks/verse (GET, POST, DELETE) with check and bulk-check endpoints
- JWT authentication required for all bookmark operations
- Multilingual error messages (Romanian/English)

Frontend Implementation:
- Chapter bookmark button in Bible page header with visual state feedback
- Individual verse bookmark icons with hover-to-reveal UI
- Highlighted background for bookmarked verses
- Efficient bulk checking for verse bookmarks per chapter
- Real-time UI updates without page refresh

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

messages/en.json

@@ -82,6 +82,8 @@
       "verse": "Verse",
       "verses": "verses",
       "save": "Save",
+      "saved": "Saved",
+      "saving": "Saving...",
       "share": "Share",
       "previousChapter": "Previous chapter",
       "nextChapter": "Next chapter",