Per-field capability confidence (DD-001) — lets consumers gate their own UI honestly (#275/M3).
Slicer-reported metadata (per-tool filaments, filamentUsage, printEstimate, thumbnails,
dialects, whitelisted raw) — for a consumer "Slice details" panel without the raw handle
(#306/#4). Capability-honest: undefined when the file carried none; individual fields are
absent (not fabricated) when a slicer didn't emit them. Purge/tower/cost are not parsed.
Parse warnings (codes/messages), so consumers can surface disclosures without the raw handle.
File-discovered geometry NOT auto-applied because the consumer configured a volume (DD-005 consumer-wins precedence) — the host decides.
Session/renderer events, re-emitted, plus the controller's own lifecycle events.