- Migration 072: widen type column to VARCHAR(20), add partial unique index for general rooms - Backend: replace brittle ON CONFLICT with explicit SELECT-then-INSERT ensureRoom helper - Frontend: show room skeletons (Общий чат + Уведомления) during load instead of spinner, hide '0 чатов' subtitle when list is empty Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>