Summary

extensions/googlechat outbound sendMedia ignores mediaLocalRoots and always uses remote-only fetch.

Repro (deterministic)

1. Open extensions/googlechat/src/channel.ts.
2. In outbound sendMedia, media loading uses runtime.channel.media.fetchRemoteMedia({ url: mediaUrl, ... }).
3. No mediaLocalRoots path is threaded, so local file paths cannot use workspace allowlisted roots.

Expected

Google Chat outbound media should support local media paths with mediaLocalRoots (same pattern used by other channels) and resolve media through runtime media loader with local roots.

Actual

mediaLocalRoots is ignored; only remote fetch path is used.

Root cause

extensions/googlechat/src/channel.ts sendMedia does not use runtime.media.loadWebMedia(..., { localRoots }).