Add autocomplete for filepaths when creating new session

[GrocerPublishAgent]

It would be really nice if the same filepicker autocomplete from the AgentInput was also available for the creating a new session with the daemon.

See my experience report video: I have to switch back to my laptop terminal to find the path. I would be completely blocked here if I was away from my computer.

https://youtu.be/Pa1lQ1EMXQw?t=402

[chphch]

Heads up — this issue looks like it was auto-closed by mistake on 2026-01-22 via PR #45 ("Fix #44: Restrict file access in RPC handlers"). PR #45 was a security fix for a separate topic; the Fix #44 reference seems to have been a number collision rather than addressing this autocomplete request.

The autocomplete behavior described above is not in main. PR #1077 implements it: live <dir>/<prefix> suggestions in the new-session path picker, fetched per-machine via machineBash with debounce + cache, and a Closes #44 link in the body.

If the feature is still wanted, this issue can be reopened so it tracks correctly with the PR. No action needed otherwise.