cd43439401
Owning the walk lets Stop interrupt a live backfill chunk instead of letting it run to its ~14.5-min time-box. ingest_core.run now polls _backfill_state at each page boundary (a short SELECT, never held across the walk) and bails with PARTIAL when an operator Stop has popped it. Latched on the first observed "running" state so a run invoked without one (unit test / stale call) never self-cancels. Progress is already checkpointed per-page, so a restart resumes from the cursor; Stop clears it for a clean reset. No UI change — the existing Stop button now just takes effect immediately. Tests: _still_running reads the state; a latched run bails PARTIAL at the next boundary when the state disappears (only the pre-cancel post ran). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>