bug: sandbox non-interactive SSH sessions missing /sandbox/.venv/bin in PATH #149

Summary

Non-interactive (pipe-mode) SSH sessions do not include /sandbox/.venv/bin in PATH. Packages installed via pip install into the writable sandbox venv are not visible when executing commands non-interactively (e.g., ssh sandbox-host 'pip install foo && python -c "import foo"').

Interactive sessions work correctly because .bashrc sets the PATH, but non-interactive sessions use the hardcoded PATH in ssh.rs.

Root Cause

The PATH is hardcoded in two places in crates/navigator-sandbox/src/ssh.rs and does not include /sandbox/.venv/bin:

• Line 656 (interactive/PTY sessions):

  .env("PATH", "/app/.venv/bin:/usr/local/bin:/usr/bin:/bin")

• Line 813 (pipe-mode/non-interactive sessions):

  .env("PATH", "/app/.venv/bin:/usr/local/bin:/usr/bin:/bin")

Expected Behavior

Both interactive and non-interactive SSH sessions should include /sandbox/.venv/bin in PATH so that user-installed packages are accessible regardless of session type.

Fix

Update both PATH entries in ssh.rs to:

.env("PATH", "/sandbox/.venv/bin:/app/.venv/bin:/usr/local/bin:/usr/bin:/bin")

/sandbox/.venv/bin must come first so it takes priority over /app/.venv/bin.

Context

This was discovered during the investigation into uv pip install failing under Landlock ABI V1 (EXDEV / cross-device link errors). The workaround switched to pip with a writable /sandbox/.venv, but the hardcoded PATH in ssh.rs was not updated to match.