feat: add direct car telemetry management

CAR_TELEMETRY.md

@@ -1,18 +1,18 @@
 # Car telemetry and retention
 
-The Pi samples the MG4 every 10 seconds while ADB is enabled. Speed, gear, and steering
-angle come from the verified ArcSoft properties. Battery values come from the read-only
-content provider in `cloud.molberg.mgutility`:
+The Pi samples the MG4 every 10 seconds while ADB is enabled. Gear and steering angle
+come from the verified ArcSoft properties. Battery values, range, and speed are read
+directly from the factory SAIC vehicle Binder service by a bundled read-only DEX probe:
 
 ```bash
-adb shell content call \
-  --uri content://cloud.molberg.mgutility.vehicle \
-  --method sample
+adb push server/assets/car-telemetry-probe.dex /data/local/tmp/pi-car-telemetry-probe.dex
+adb shell CLASSPATH=/data/local/tmp/pi-car-telemetry-probe.dex \
+  app_process /system/bin cloud.molberg.picarprobe.CarTelemetryProbe
 ```
 
-The provider must be present in the installed MG Utility APK. Until it connects to the
-SAIC vehicle service, battery fields remain unavailable while the ArcSoft signals and
-their history continue working.
+The helper is not installed and has no dependency on MG Utility. It performs only known
+getter transactions. If the factory service is unavailable, battery fields remain
+unavailable while the ArcSoft signals and their history continue working.
 
 ## Storage limits
 
@@ -36,5 +36,5 @@ well below 150 MB, although SQLite page allocation and filesystem details can va
 - Peak values mean the highest value observed at a 10-second sampling point. They are
   not guaranteed to capture a shorter event between samples.
 
-The collector sends no vehicle-control calls. Installing MG Utility and enabling ADB
-remain parked-vehicle administration tasks.
+The collector sends no vehicle-control calls. Enabling and authorizing ADB remains a
+parked-vehicle administration task.