Summary

extensions/imessage plugin outbound sendMedia drops mediaLocalRoots before calling sendMessageIMessage.

Repro (deterministic)

1. Open extensions/imessage/src/channel.ts.
2. In sendIMessageOutbound, note the options passed to send(...) do not include mediaLocalRoots.
3. Open src/imessage/send.ts; sendMessageIMessage supports mediaLocalRoots and uses it in outbound attachment resolution.

Expected

mediaLocalRoots provided to outbound sendMedia should be forwarded to sendMessageIMessage so local media paths allowed by workspace roots resolve.

Actual

mediaLocalRoots is dropped in the extension adapter, so local-root context is lost before media resolution.

Root cause

sendIMessageOutbound and outbound.sendMedia in extensions/imessage/src/channel.ts do not thread mediaLocalRoots through.