Pre-tracker historical knowledge has zero rows in
knowledge_processing_spans but parse_status correctly reads
"completed" or "failed". The /spans handler was synthesizing five
"pending" placeholders unconditionally, so legacy completed documents
rendered as if they were stuck waiting in the queue forever.
buildSpanTree now takes parse_status and chooses the placeholder
status accordingly:
- ParseStatusCompleted -> done
- ParseStatusFailed -> failed
- everything else -> pending (existing behaviour)
Real rows always take precedence; this only changes what we put in
the gaps. So healthy in-flight parses (parse_status=processing,
some real rows, some still pending) keep showing pending placeholders
exactly as before — the synthesized "completed" inference only fires
when the parse already hit terminal state.
Adds TestBuildSpanTree_LegacyCompletedRendersAsDone covering both
the completed-legacy and failed-legacy branches.
wizardchen
5ffc755e76