Add user comment history endpoint for profile pages with: - Lexicon definition following AT Protocol conventions - Handler with proper error handling (400/404/500 distinction) - Cursor-based pagination with composite key (createdAt|uri) - Optional community filtering - Viewer vote state population for authenticated users - Comprehensive handler tests (15 tests) - Comprehensive service tests (13 tests) Key fixes from PR review: - resolutionFailedError now returns 500 (not 400) - Added warning log for missing votes table - Improved SQL parameter documentation for cursor filters 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>