Removes the entire fallback submitter mechanism: ckpool patch 0004,
the blocksubmit package, the wiring in main.go, the config fields,
the aggregator's fallback counters and snapshot fields, the healthz
fallback fields, and the TS type fields plus the HealthBanners
fallback alert.
Reasoning: ckpool's primary bitcoind submission must remain the
single source of truth, and getting the parallel "race a fallback
during the submit" semantics right is more architectural complexity
than the marginal reliability gain justifies. The original upstream
behavior — submit to bitcoind, retry indefinitely if unavailable —
is what we want.
Kept intact:
* Submit-attempt vs confirmed counters (block_submit_attempts /
block_submits_confirmed). Useful on their own as a "did bitcoind
confirm the submission?" signal.
* HealthBanners shows submit_gap and zmq_stale only.
* /healthz exposes submit_gap, zmq_stale, etc.
* All P0 reliability work (tailer cursor, reconcile loop, reorg
detection, multi-solve guard) and other P1 (RPC retry, WS
back-pressure, ZMQ tracking, startup readiness gate).
satoshi
1dcf087842