Bootstrap endpoint skips knowledge reports — only backfills Q&A extraction pipeline

The POST /admin/graph/bootstrap endpoint runs scheduleBackfill() which enqueues all questions with answers for LLM extraction, then flushAllLanes() which flushes the high/normal/low extraction queues, then runNightlyPipeline(). However, knowledge reports are completely skipped: scheduleBackfill() only queries the answers table, and flushAllLanes() only flushes the three Q&A lanes — not the graph-extract-report queue. This means hitting bootstrap after adding report support leaves all reports unprocessed in Neo4j (structural node only, no semantic extraction via Apollo/Dionysus).