port dashcamd: hardware-encoded MP4 dashcam

VisionIPC frames from camerad → OMX H.264 hardware encoder → 3-min MP4
segments + SRT GPS subtitles in /data/media/0/videos/<trip>/. Manages
its own trip lifecycle (WAITING/RECORDING/IDLE_TIMEOUT) and writes
DashcamState/DashcamFrames memory params for the UI's Status window.
Honors DashcamShutdown for graceful close before power-off.

Files added:
- selfdrive/clearpilot/dashcamd.cc + SConscript

Files modified:
- selfdrive/frogpilot/screenrecorder/omx_encoder.{cc,h}: ported broken's
  version, which adds encode_frame_nv12() (direct NV12 input from camerad,
  alongside the existing encode_frame_rgba used by the disabled screen
  recorder) and simplifies the libyuv conversion paths to NEON-only since
  this device is aarch64.
- selfdrive/SConscript: register selfdrive/clearpilot/SConscript so the
  dashcamd binary is part of the build.
- selfdrive/manager/process_config.py:
  - camerad gating driverview → always_run so dashcamd can record the
    moment ignition+drive arrives without waiting for camera startup.
  - Register dashcamd as NativeProcess gated always_run.
- system/loggerd/deleter.py:
  - MIN_BYTES 5 GB → 9 GB to leave headroom for dashcam footage.
  - delete_oldest_video(): trip-aware cleanup. Drops entire oldest trip
    dir first; if only the active trip remains, drops oldest segment
    inside it; cleans up legacy flat .mp4s too.
  - cleanup_log2(): keeps /data/log2 session logs under 4 GB total.
  - Hooked into deleter_thread: video first when out of bytes/percent;
    log2 quota check on the idle path. New code uses print(stderr) per
    the no-cloudlog rule.

Verified: built clean, manager started, dashcamd in WAITING state
(DashcamState=waiting, DashcamFrames=0), camerad running, no errors.

selfdrive/manager/process_config.py

@@ -54,7 +54,9 @@ def allow_uploads(started, params, CP: car.CarParams) -> bool:
 procs = [
   DaemonProcess("manage_athenad", "selfdrive.athena.manage_athenad", "AthenadPid"),
 
-  NativeProcess("camerad", "system/camerad", ["./camerad"], driverview),
+  # CLEARPILOT: camerad runs always (was driverview) so dashcamd can record
+  # the moment ignition+drive-gear arrives without waiting for camera startup.
+  NativeProcess("camerad", "system/camerad", ["./camerad"], always_run),
   NativeProcess("logcatd", "system/logcatd", ["./logcatd"], allow_logging),
   NativeProcess("proclogd", "system/proclogd", ["./proclogd"], allow_logging),
   PythonProcess("logmessaged", "system.logmessaged", allow_logging),
@@ -89,6 +91,9 @@ procs = [
   # CLEARPILOT: speed/cruise overlay daemon. Reads gpsLocation + carState, writes display
   # params for the onroad UI; asserts ClearpilotPlayDing on speed-limit warning transitions.
   PythonProcess("speed_logicd", "selfdrive.clearpilot.speed_logicd", only_onroad),
+  # CLEARPILOT: dashcam — VisionIPC frames → OMX H.264 → 3-min MP4 segments + SRT
+  # GPS subtitles in /data/media/0/videos/. Manages its own trip lifecycle.
+  NativeProcess("dashcamd", "selfdrive/clearpilot", ["./dashcamd"], always_run),
   # PythonProcess("ugpsd", "system.ugpsd", only_onroad, enabled=TICI),
   #PythonProcess("navd", "selfdrive.navd.navd", only_onroad),
   PythonProcess("pandad", "selfdrive.boardd.pandad", always_run),