modeld two-state; UI: immediate blank on ignition off; READY splash on wake

- modeld: simplified to 0fps (standstill or parked) or 20fps. Removed
  4/10fps reduced-rate path, republish caching, FPCC/liveCalibration
  reads, and ModelFps per-cycle param writes.
- ui.cc updateWakefulness: ignition on→off now resets interactive_timeout
  to 0 for immediate screen blank. Tap still wakes via existing handler.
- home.cc offroadTransition(false): reset ready->has_driven to false so
  the READY text appears on fresh ignition, not the textless post-drive
  splash.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

selfdrive/ui/ui.cc

@@ -558,7 +558,10 @@ void Device::updateWakefulness(const UIState &s) {
   }
 
   if (ignition_state_changed) {
-    if (ignition_on && s.scene.screen_brightness_onroad == 0 && !s.scene.standby_mode) {
+    if (!ignition_on) {
+      // CLEARPILOT: ignition on→off blanks the screen immediately (tap still wakes).
+      resetInteractiveTimeout(0, 0);
+    } else if (s.scene.screen_brightness_onroad == 0 && !s.scene.standby_mode) {
       resetInteractiveTimeout(0, 0);
     } else {
       resetInteractiveTimeout(s.scene.screen_timeout, s.scene.screen_timeout_onroad);