Add firehose:watch ace command and fix lint
The ace command wires the FirehoseConsumer to the container-resolved
ClickHouseStore and cursor IO, then blocks on start() with SIGTERM/SIGINT
handlers that flush buffers cleanly before exit. URL resolution prefers
FIREHOSE_JETSTREAM_URL → JETSTREAM_URL → the default jetstream2.us-east
endpoint.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>