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.

common/params.cc

@@ -243,6 +243,30 @@ std::unordered_map<std::string, uint32_t> keys = {
 
     {"CPTLkasButtonAction", PERSISTENT},
     {"ScreenDisplayMode", PERSISTENT},
+
+    // CLEARPILOT memory params (live at /dev/shm/params; tmpfs is volatile so
+    // these reset on reboot regardless of registration flag).
+    {"CarIsMetric", PERSISTENT},
+    {"ClearpilotCruiseWarning", PERSISTENT},
+    {"ClearpilotCruiseWarningSpeed", PERSISTENT},
+    {"ClearpilotHasSpeed", PERSISTENT},
+    {"ClearpilotIsMetric", PERSISTENT},
+    {"ClearpilotPlayDing", PERSISTENT},
+    {"ClearpilotShowHealthMetrics", PERSISTENT},
+    {"ClearpilotSpeedDisplay", PERSISTENT},
+    {"ClearpilotSpeedLimitDisplay", PERSISTENT},
+    {"ClearpilotSpeedUnit", PERSISTENT},
+    {"DashcamFrames", PERSISTENT},
+    {"DashcamShutdown", PERSISTENT},
+    {"DashcamState", PERSISTENT},
+    {"IsDaylight", PERSISTENT},
+    {"ModelFps", PERSISTENT},
+    {"ModelStandby", PERSISTENT},
+    {"ModelStandbyTs", PERSISTENT},
+    {"ScreenRecorderDebug", PERSISTENT},
+    {"ShutdownTouchReset", PERSISTENT},
+    {"TelemetryEnabled", PERSISTENT},
+    {"VpnEnabled", PERSISTENT},
     
     {"RadarDist", PERSISTENT},
     {"ModelDist", PERSISTENT},