Function check_passwordless_sudo_available 

pub fn check_passwordless_sudo_available() -> Result<bool, String>

What: Check if passwordless sudo is available for the current user.

Inputs:

• None (checks system configuration).

Output:

• Ok(true) if passwordless sudo is available, Ok(false) if not, or Err(String) on error.

Errors

• Returns Err if the check cannot be executed (e.g., sudo not installed).

Details:

• Uses sudo -n true to test if sudo can run without password.
• -n: Non-interactive mode (fails if password required).
• true: Simple command that always succeeds if sudo works.
• Returns Ok(false) if sudo is not available or requires a password.
• Testing: Only when PACSEA_INTEGRATION_TEST=1 is set (test harness), the env var PACSEA_TEST_SUDO_PASSWORDLESS is honored: “1” = available, “0” = unavailable. In production (when PACSEA_INTEGRATION_TEST is not set), PACSEA_TEST_SUDO_PASSWORDLESS is ignored so the only way to enable passwordless sudo is via use_passwordless_sudo in settings.