register clearpilot memory params and seed defaults in manager_init

Scaffolding for the upcoming UI port. Registers the keys the new C++
UI and SpeedState daemon will read/write, and seeds /dev/shm/params
defaults at manager start so first-readers don't see missing keys
before writers spin up.

Keys registered: CarIsMetric, ClearpilotCruiseWarning,
ClearpilotCruiseWarningSpeed, ClearpilotHasSpeed, ClearpilotIsMetric,
ClearpilotPlayDing, ClearpilotShowHealthMetrics,
ClearpilotSpeedDisplay, ClearpilotSpeedLimitDisplay,
ClearpilotSpeedUnit, DashcamFrames, DashcamShutdown, DashcamState,
IsDaylight, ModelFps, ModelStandby, ModelStandbyTs,
ScreenRecorderDebug, ShutdownTouchReset, TelemetryEnabled, VpnEnabled.

PERSISTENT registration here is purely a no-op placeholder: the actual
storage is /dev/shm/params (tmpfs), which clears on every reboot
regardless. Bench-mode keys (Bench*, ClpUiState, LogDirInitialized)
not registered yet — they'll come with their respective features.

selfdrive/manager/manager.py

@@ -301,6 +301,32 @@ def manager_init(frogpilot_functions) -> None:
     else:
       params_storage.put(k, params.get(k))
 
+  # CLEARPILOT memory-param defaults. /dev/shm/params is on tmpfs so these
+  # reset on every boot anyway; we still set them so first-readers don't see
+  # missing keys before the writer process has spun up.
+  params_memory = Params("/dev/shm/params")
+  for k, v in [
+    ("CarIsMetric", "0"),
+    ("ClearpilotCruiseWarning", ""),
+    ("ClearpilotCruiseWarningSpeed", ""),
+    ("ClearpilotHasSpeed", "0"),
+    ("ClearpilotIsMetric", "0"),
+    ("ClearpilotPlayDing", "0"),
+    ("ClearpilotSpeedDisplay", ""),
+    ("ClearpilotSpeedLimitDisplay", "0"),
+    ("ClearpilotSpeedUnit", "mph"),
+    ("DashcamFrames", "0"),
+    ("DashcamShutdown", "0"),
+    ("DashcamState", "stopped"),
+    ("ModelFps", "20"),
+    ("ModelStandby", "0"),
+    ("ModelStandbyTs", "0"),
+    ("ShutdownTouchReset", "0"),
+    ("TelemetryEnabled", "0"),
+    ("VpnEnabled", "1"),
+  ]:
+    params_memory.put(k, v)
+
   # Create folders needed for msgq
   try:
     os.mkdir("/dev/shm")