Per-stage planar-graph statistics — surfaced for diagnostics.
Per-region builder result. Empty when dryRun: true.
Detected rooms skipped because they overlap an existing space.
Total walls considered (existing + overlay) on the storey.
Walls that contributed an axis segment to the planar graph.
Walls dropped by the extractor, with the reason (best-effort).
Enclosed regions detected (after min-area + outer-face filter).