V3 deterministic media-metadata capability pack. By-value connector composition (service_kind=cli, no separate ingredient): one local mediainfo CLI ingredient exposes readiness, supported-parameter discovery, human-readable media inspection, and JSON metadata for one trusted local media/document path. The metadata operations are read-only and path-based stdout values because the metadata itself is the requested output; they intentionally do not combine file_ref materialization with stdout capture. Requires mediainfo on PATH (Debian/Ubuntu: apt install mediainfo; macOS: brew install media-info). Local and no-egress; no shell wrapper, arbitrary MediaInfo flags, recursive directory scan, remote URL fetch, or file output path is exposed.