- Collapse migrations 000052 (flat stages) + 000053 (span tree) into a
single 000052_knowledge_processing_spans migration; the flat stages
table never escaped this branch and the create-then-drop sequence had
no value.
- BeginStage: detect an existing (kid, attempt, stage) row before
inserting and reuse its span_id with reset state, so re-entry from
asynq retries or adjacent code paths no longer produces duplicate
timeline segments.
- FailSpan: when sibling-stage cascade flips a dependent stage to
cancelled, also CancelDescendants on its subtree so already-running
subspans (embedding.batch[i] etc.) cannot remain as orphan running
rows under a cancelled parent.
- Dead-letter callback: replace two sequential UpdateKnowledgeColumn
writes with a single UpdateKnowledgeColumns map update so we cannot
end up with parse_status=failed and stale error_message (or vice
versa) when one of the two writes fails.
- touchKnowledgeHeartbeat: skip subspan/generation transitions; only
root and stage transitions poke knowledge.updated_at. Spans-table
MAX(updated_at) already covers subspan progress for housekeeping, so
this avoids 2*N+ UPDATE bursts on the same hot row when a multimodal
stage fans out to many images.
- Add regression tests for the BeginStage idempotency contract and the
cascade-into-subspans behaviour.
wizardchen
c82b098f44