add source to stream output

[KM-565] sync catalog on document and db client deletion

[NOTICKET] cleanup PR: wire ChatHandler, drop Phase 1 remnants, implement catalog rebuild

[KM-556][KM-562] fix tabular catalog pipeline: trigger wiring, parquet upload, lazy Azure init, backfill script

[KM-560][KM-561] drop catalog LLM enrichment + rename store to data_catalog + add /data-catalog index endpoint

fixes: chain singleton, parquet logger, SSE event consistency, remove double DB fetch

[KM-556] rewire chat stream endpoint to Phase 2 IntentRouter + AnswerAgent + QueryService

[KM-556] wire document process endpoint to on_tabular_uploaded[KM-556] wire document process endpoint to on_tabular_uploaded

[KM-553] migrate retrieval layer and remove obsolete rag/tools modules

[KM-438][KM-439] Improve Retrieval and Querying feature (#15)

Merge dev_new to main (improve retriever and add querying) (#13)

[NOTICKET] fixed single source into multiple sources (#12)

[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