emitTreeEvent and emitCommentEvent were byte-identical (same room resolution,
spaceHasRestrictions gate, hasRestrictedAncestor, authorized-only vs broadcast
fallback). Collapse the body into one private emitRestrictedAwareToSpace; both
stay thin wrappers with unchanged signatures, so the restriction-routing gate
lives in exactly one place. Adds coverage for the comment entry point.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>