After the full snapshot downloads, continuously re-probe all fast sources
for newer incrementals until the best available is within convergence_slots
(default 500) of head. Each iteration finds the highest-slot incremental
matching our full snapshot's base slot, downloads it (replacing any previous),
and checks the gap to mainnet head.
- Extract probe_incremental() from inline re-probe code
- Add convergence_slots param to download_best_snapshot() (default 500)
- Add --convergence-slots CLI arg
- Pass SNAPSHOT_CONVERGENCE_SLOTS env var from entrypoint.py
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>