fix(scanner): auto-restart block sync on crash instead of stopping#4
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Catch-up sync ran inside a single try/catch alongside the WebSocket startup. When a block failed (e.g. a sustained RPC outage that exhausted the per-request retries), runCatchup re-threw, the outer catch logged "API will run without scanner", and the real-time WS path never even started — sync stopped for good until a process restart. Wrap catch-up in a supervisor that restarts it with exponential backoff. Progress is checkpointed per block, so each restart resumes from the last synced block with no lost or duplicated work. Once catch-up completes, the (self-healing) WS subscription path starts as before. The supervisor runs detached so a slow/retrying catch-up never blocks startup, and a shutdown flag stops the loop cleanly on SIGINT/SIGTERM. Backoff is configurable via SCANNER_RESTART_BASE_DELAY_MS (5s) and SCANNER_RESTART_MAX_DELAY_MS (60s). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01BEG3HfBuwNhijzL168Rkvv
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Catch-up sync ran inside a single try/catch alongside the WebSocket startup. When a block failed (e.g. a sustained RPC outage that exhausted the per-request retries), runCatchup re-threw, the outer catch logged "API will run without scanner", and the real-time WS path never even started — sync stopped for good until a process restart.
Wrap catch-up in a supervisor that restarts it with exponential backoff. Progress is checkpointed per block, so each restart resumes from the last synced block with no lost or duplicated work. Once catch-up completes, the (self-healing) WS subscription path starts as before. The supervisor runs detached so a slow/retrying catch-up never blocks startup, and a shutdown flag stops the loop cleanly on SIGINT/SIGTERM.
Backoff is configurable via SCANNER_RESTART_BASE_DELAY_MS (5s) and SCANNER_RESTART_MAX_DELAY_MS (60s).
Claude-Session: https://claude.ai/code/session_01BEG3HfBuwNhijzL168Rkvv