feat: realtime ETL offload to S3 + live business dashboards

- etl_offload.py: autonomous agent backfills/tails source DBs (PG/MySQL/
  Mongo/Cassandra) to S3 as Parquet in small chunks, accumulates a live
  federated business matrix (/api/etl/status, /api/etl/business, /run, /config).
- storage_s3.py: buffer generated CDC + masked curated rows to S3, overlay
  live last-write into analytics; put_object_bytes for Parquet parts.
- trino_federated.py: capture generated rows + archive to S3; generator_active.
- dataflow.py: pulse generate + kafka/spark->S3 archive edges when active.
- StorageView: realtime ETL ingest panel; TrinoFederationView: realtime
  business KPIs/charts from /api/etl/business.
- ChangesView: top KPIs/charts now overlay the live WS stream on server stats
  so they update in lock-step with the bottom feed; faster 2.5s refresh.
- useCommandCenter: retain 800 live CDC changes.

api/requirements.txt

@@ -16,3 +16,4 @@ python-pptx==1.0.2
 boto3==1.35.99
 paramiko==3.5.0
 aiokafka==0.12.0
+pyarrow==18.1.0