park CPU savings + fix early shutdown on virtual battery capacity

controlsd: in park+ignition-on, run full step() only every 10th cycle.
data_sample still runs every cycle (CAN parse, button detection) and
card.controls_update still runs every cycle (CAN TX heartbeat, counter
increments). Skipped cycles re-send cached controlsState/carControl so
downstream freq_ok stays OK. Button edge handling + display-mode
transitions extracted to handle_screen_mode() and called every cycle so
debug-button presses aren't dropped. controlsd: 55% → 30% CPU in park.

dmonitoringmodeld: subscribe to carState; at standstill, skip model.run
and re-publish last inference. driverStateV2 continues flowing at 10Hz
with known-good last face data (driver can't become distracted relative
to a stopped car). ~5% CPU saved.

power_monitoring: remove the `car_battery_capacity_uWh <= 0` shutdown
trigger. That virtual capacity counter floor-limits to 3e6 µWh on boot
and drains in ~12 min at typical device power, so a short drive (that
doesn't fully recharge the 30e6 µWh virtual cap) followed by a quick
store stop would trip shutdown well before the 30-min idle timer. The
real car-battery-voltage protection (low_voltage_shutdown at 11.8V with
60s debounce) is kept.

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

selfdrive/thermald/power_monitoring.py

@@ -122,7 +122,13 @@ class PowerMonitoring:
                             offroad_time > VOLTAGE_SHUTDOWN_MIN_OFFROAD_TIME_S)
     should_shutdown |= offroad_time > self.device_shutdown_time
     should_shutdown |= low_voltage_shutdown
-    should_shutdown |= (self.car_battery_capacity_uWh <= 0)
+    # CLEARPILOT: removed `car_battery_capacity_uWh <= 0` trigger. That's a virtual
+    # capacity counter floor-limited to 3e6 µWh on boot which drains in ~12 min at
+    # typical device power. With a short drive that doesn't fully recharge (charges
+    # at 45W, cap 30e6 µWh = 36 min to full), a quick store stop could trip shutdown
+    # well before the intended 30-min idle timer. The real protection we want here
+    # is the car battery voltage check (kept above) — the virtual counter is now
+    # retained only for telemetry.
     should_shutdown &= not ignition
     should_shutdown &= (not self.params.get_bool("DisablePowerDown"))
     should_shutdown &= in_car