Add production-ready migration script to update existing community handles from plural (.communities.) to singular (.community.) format. Migration features: - Safe UPDATE using REPLACE for targeted changes - Verification checks to ensure migration completion - Rollback script for emergency reversion - Error handling with informative messages Example transformations: - gardening.communities.coves.social → gardening.community.coves.social - gaming.communities.coves.social → gaming.community.coves.social This migration is required for the .communities → .community naming convention change to align with AT Protocol lexicon standards (all record types use singular form). 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>