SQLite does not guarantee row order without ORDER BY, even with LIMIT.
This was a systemic issue found during a multi-pass bug hunt:
Production queries (explain.rs):
- Outgoing reference query: ORDER BY target_entity_type, target_entity_iid
- Incoming reference query: ORDER BY source_entity_type, COALESCE(iid)
Without these, robot mode output was non-deterministic across calls,
breaking clients expecting stable ordering.
Test helper queries (5 locations across 3 files):
- discussions_tests.rs: get_discussion_id()
- mr_discussions.rs: get_mr_discussion_id()
- queue.rs: setup_db_with_job(), release_all_locked_jobs_clears_locks()
Currently safe (single-row inserts) but would break silently if tests
expanded to multi-row fixtures.
1. fetch_open_threads: replace N+1 loop (2 queries per thread) with a
single query using correlated subqueries for note_count and started_by.
2. extract_key_decisions: track consumed notes so the same note is not
matched to multiple events, preventing duplicate decision entries.
3. build_timeline_excerpt_from_pipeline: log tracing::warn on seed/collect
failures instead of silently returning empty timeline.
entity_references.target_entity_iid is nullable (unresolved cross-project
refs), and COALESCE(i.iid, mr.iid) returns NULL for orphaned refs.
Both paths caused rusqlite InvalidColumnType errors when fetching i64.
Added IS NOT NULL filters to both outgoing and incoming reference queries.
