[KM-564] fix source, now shows name instead of id. added diff retrieval vs catalog

add source to stream output

[KM-565] fix catalog timestamps, count_distinct logic, and query debug logging

[KM-564] fix render and sql error

[KM-556] move parquet_service from knowledge/ to storage/

Merge DB bundle (PR2b/4/5/6/7) into pr/1 + reconcile PROGRESS.md

[NOTICKET] IntentRouter + planner + dispatcher + QueryService + AnswerAgent + ChatHandler

detect XLSX by filename, not table count

eat(query): PandasCompiler + TabularExecutor (PR3-TAB)

[KM 556] add columns field to QueryResult + update DbExecutor

[NOTICKET] SqlCompiler (Postgres) + DbExecutor

initial structure

initial commit