feat: add confluence/slack search tools, chat history, cloud Qdrant support, sync trigger fixes

feat: implement NL-to-SQL agent with PostgreSQL integration and enhance related documentation

feat: RBAC foundation — workspaces, channels, role-based access

Fix Qdrant search API, add Supabase writes to agent pipelines, pin qdrant-client 1.17.1

Fix startup imports and add graph_store module

Add agent and ingestion modules for Enterprise Knowledge Copilot