docs(pkb): Add development records and update system status

Summary:
- Add PKB module development record for 2026-01-07
- Create PKB module status document (00-模块当前状态与开发指南.md)
- Update system status document to v2.7

Documents added:
- docs/03-业务模块/PKB-个人知识库/06-开发记录/2026-01-07_PKB模块前端V3设计实现.md
- docs/03-业务模块/PKB-个人知识库/00-模块当前状态与开发指南.md

Documents updated:
- docs/00-系统总体设计/00-系统当前状态与开发指南.md

PKB module progress: 75% complete
- Frontend Dashboard: 90%
- Frontend Workspace: 85%
- 3 work modes implemented
- Batch processing API pending debug

backend/prisma/manual-migrations/001_add_postgres_cache_and_checkpoint.sql

@@ -97,5 +97,6 @@ ORDER BY ordinal_position;
 
 
 
+
 
 

backend/prisma/manual-migrations/run-migration-002.ts

@@ -110,5 +110,6 @@ runMigration()
 
 
 
+
 
 

backend/prisma/migrations/20251208_add_column_mapping/migration.sql

@@ -44,5 +44,6 @@ COMMENT ON COLUMN "dc_schema"."dc_tool_c_sessions"."column_mapping" IS '列名
 
 
 
+
 
 

backend/prisma/migrations/create_tool_c_session.sql

@@ -71,5 +71,6 @@ COMMENT ON COLUMN dc_schema.dc_tool_c_sessions.expires_at IS '过期时间（创
 
 
 
+