acp: Receive available commands over notifications (#37499)

See: https://github.com/zed-industries/agent-client-protocol/pull/62

Release Notes:

- Agent Panel: Fixes an issue where Claude Code would timeout waiting
for slash commands to be loaded

Co-authored-by: Cole Miller <cole@zed.dev>
d6f0811dabAgus Zubiaga committed on 9/3/2025, 10:24:59 PM· committed by GitHubparentbe0bb4a
9 files changedLine totals unavailable