Replace the runtime IMGUI (OnGUI) HUD with a binder that drives the authored
MatchHudCanvas widgets via [SerializeField] references (Canvas / Phase /
Time / Crosshair). Visibility toggles Canvas.enabled instead of the
GameObject, so Update keeps polling while hidden; an Awake guard disables
the component on unwired references. Drop the AddComponent<MatchHud>()
bootstrap in MatchManager - the component now lives on the scene canvas.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>