Function AirStart 

pub async fn AirStart(
    _ApplicationHandle: &AppHandle,
    _Environment: &Arc<MountainEnvironment>,
) -> Result<(), String>

Spawn and connect to the Air daemon. Returns Ok(()) regardless of outcome - Air is non-essential for workbench operation; Mountain gracefully degrades when Air is unavailable.

Spawn is gated on:

• The AirIntegration Cargo feature (compile-time).
• The Spawn env var (runtime; mirrors CocoonStart semantics).