[NOTICKET] add db_client for querying

[KM-507] add changes to methods

[KM-507] add multiple retrieval method to compare (dense, mmr, bm25, hybrid)

[NOTICKET] fixed multiple sources

[NOTICKET] fix single source to multiple sources

[KM-438][KM-439] framework for knowledge retriever

[NOTICKET][document]: make a clean output to status error unsupported file type

[NO TICKET][document]: delete vector embedding on table langchain_pg_embedding if user delete document on knowledge

[NO TICKET][document]: add updated_at on metadata

[NOTICKET] add updated_at field for metadata & delete old embedding before appending

[NOTICKET] add total token logging

[KM-496] [DED][AI] Fix Response data structure for field sources (db flow)

[NOTICKET] [document]: add doctypes endpoint (#7)

[NOTICKET][DB] add endpoints for dbtypes (#6)

[KM-493] [DED][AI] Fix source extraction in chat

[KM-436][KM-437] add and modify for database and document pipeline (#3)

[NOTICKET] Init db_client endpoint

[KM-467] [DED][AI] Orchestration Agent - Init