Merge remote-tracking branch 'origin/master' into ji

# Conflicts:
#	frontend-web/src/core/page-layout/sidebar-menu.ts
#	frontend-web/src/core/system-settings/api.ts
#	frontend-web/src/core/system-settings/hooks.ts
#	frontend-web/src/strategy-components/Header.tsx
#	offline-backend-20260512/backend/CLAUDE.md
#	offline-backend-20260512/backend/app/gateway/routers/system_settings.py
#	offline-backend-20260512/backend/packages/harness/deerflow/config/system_settings.py
#	offline-backend-20260512/backend/scripts/sql/column_additions_mysql.sql

offline-backend-20260512/backend/scripts/sql/column_additions_mysql.sql

@@ -85,6 +85,10 @@ CALL _add_column_if_missing('roundtable_drafts', 'task_id', 'VARCHAR(128) NULL D
 --                     ORM: RoundtableJobRow.orchestration_plan = PortableLongText(LONGTEXT), nullable。
 CALL _add_column_if_missing('roundtable_jobs', 'orchestration_plan', 'LONGTEXT NULL DEFAULT NULL');
 
+-- seat_mode: 业务链条「默认席位执行模式」(flash/thinking/pro/ultra),对应 migration 20260615_01。
+--            选入研讨时弹窗默认用它(仍可临时改)。ORM: RoundtableChainRow.seat_mode = String(16), nullable。
+CALL _add_column_if_missing('roundtable_chains', 'seat_mode', 'VARCHAR(16) NULL DEFAULT NULL');
+
 -- ---- 岗位 (positions) 订阅系统,对应 migration 20260616_01 -------------------
 -- positions / position_tag_bindings 是【新表】,由 create_all 自动建,无需补列。
 -- 以下是给【已存在的表】补的列: