SSH commands freeze on interactive input — need -T flag and stdin redirect

[nsluss]

Problem

When pi is connected to a remote VM via vers_vm_use, running a bash command that prompts for interactive input (e.g. tailscale up, apt-get install with Y/N) causes the pi session to freeze permanently (or until the 120s timeout).

Root Cause

In extensions/vers-vm.ts, the execStreaming() and exec() methods spawn SSH without:

1. The -T flag (disable pseudo-terminal allocation)
2. Stdin redirect from /dev/null for remote commands

SSH forwards stdin to the remote process. When the remote process blocks on input, SSH blocks, pi blocks. Permanent freeze.

Proposed Fix

Two changes in extensions/vers-vm.ts:

1. Add -T to sshArgs() to disable PTY allocation
2. Wrap remote commands: < /dev/null ${command} in both execStreaming() and exec()

This prevents remote processes from ever blocking on stdin, while preserving stdout/stderr capture.

Context

• Discovered by noah-fleet agents repeatedly freezing when running Tailscale setup, git operations, and package installs on VMs
• Existing 120s timeout is a mitigation, not a fix — commands still block for the full timeout before dying
• Issue SSH commands hang chat for extended periods - need timeout/backgrounding #1 was closed with just the timeout addition
• Scully-9 investigation report: https://e0eab0bb-31f1-460d-8a2a-2b4bcdb8ac82.vm.vers.sh:3000/reports/share/1df99de6-8463-4fe5-808a-e5348a2eea9d