Add rich message segment support enabling structured content (text, images, votes, mentions) in posts and comments. Includes segments field in models, DTOs, handlers, and services. Also adds @mention notification processing and migrates vote data to embedded segments.
Add admin comment moderation endpoints (single and batch) and introduce a three-tier moderation system (pass/review/block) for content flagged by AI. Content with unclear violations is now held for manual review instead of being auto-rejected. Deleted the legacy audit_service.go in favor of the unified hook-based moderation system.
Implement sensitive word filtering feature with configurable database and Redis
support. Add security enhancements including WebSocket origin validation, improved
password strength requirements, timing attack prevention, and production JWT secret
validation. Add batch operation validation limits and optimize user blocking
queries with subqueries.
BREAKING CHANGE: Password validation now requires minimum 8 characters with uppercase,
lowercase, and digit (was 6-50 characters without complexity requirements)
