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.

system/loggerd/deleter.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 import os
 import shutil
+import sys
 import threading
 from openpilot.system.hardware.hw import Paths
 from openpilot.common.swaglog import cloudlog
@@ -8,11 +9,17 @@ from openpilot.system.loggerd.config import get_available_bytes, get_available_p
 from openpilot.system.loggerd.uploader import listdir_by_creation
 from openpilot.system.loggerd.xattr_cache import getxattr
 
-MIN_BYTES = 5 * 1024 * 1024 * 1024
+# CLEARPILOT: bumped from 5 GB to 9 GB so dashcam footage has headroom
+MIN_BYTES = 9 * 1024 * 1024 * 1024
 MIN_PERCENT = 10
 
 DELETE_LAST = ['boot', 'crash']
 
+# CLEARPILOT: dashcam footage directory (trip dirs YYYYMMDD-HHMMSS/ with .mp4 segments)
+VIDEOS_DIR = '/data/media/0/videos'
+# CLEARPILOT: max total size for /data/log2 session logs
+LOG2_MAX_BYTES = 4 * 1024 * 1024 * 1024
+
 PRESERVE_ATTR_NAME = 'user.preserve'
 PRESERVE_ATTR_VALUE = b'1'
 PRESERVE_COUNT = 5
@@ -44,12 +51,105 @@ def get_preserved_segments(dirs_by_creation: list[str]) -> list[str]:
   return preserved
 
 
+def delete_oldest_video():
+  """CLEARPILOT: prune dashcam footage when disk space is low.
+  Trip directories are /data/media/0/videos/YYYYMMDD-HHMMSS/ containing .mp4
+  segments. Deletes entire oldest trip directory first. If only one trip
+  remains (the active one), deletes individual segments oldest-first within
+  it. Also cleans up legacy flat .mp4 files.
+  Returns True if something was deleted."""
+  try:
+    if not os.path.isdir(VIDEOS_DIR):
+      return False
+
+    legacy_files = []
+    trip_dirs = []
+    for entry in os.listdir(VIDEOS_DIR):
+      path = os.path.join(VIDEOS_DIR, entry)
+      if os.path.isfile(path) and entry.endswith('.mp4'):
+        legacy_files.append(entry)
+      elif os.path.isdir(path):
+        trip_dirs.append(entry)
+
+    if legacy_files:
+      legacy_files.sort()
+      delete_path = os.path.join(VIDEOS_DIR, legacy_files[0])
+      print(f"CLP deleter: deleting legacy video {delete_path}", file=sys.stderr, flush=True)
+      os.remove(delete_path)
+      return True
+
+    if not trip_dirs:
+      return False
+
+    trip_dirs.sort()  # timestamp names = chronological order
+
+    if len(trip_dirs) > 1:
+      delete_path = os.path.join(VIDEOS_DIR, trip_dirs[0])
+      print(f"CLP deleter: deleting trip {delete_path}", file=sys.stderr, flush=True)
+      shutil.rmtree(delete_path)
+      return True
+
+    # Only one trip left (likely active) — drop its oldest segment
+    trip_path = os.path.join(VIDEOS_DIR, trip_dirs[0])
+    segments = sorted(f for f in os.listdir(trip_path) if f.endswith('.mp4'))
+    if not segments:
+      return False
+    delete_path = os.path.join(trip_path, segments[0])
+    print(f"CLP deleter: deleting segment {delete_path}", file=sys.stderr, flush=True)
+    os.remove(delete_path)
+    return True
+  except OSError as e:
+    print(f"CLP deleter: issue deleting video from {VIDEOS_DIR}: {e}", file=sys.stderr, flush=True)
+    return False
+
+
+def cleanup_log2():
+  """CLEARPILOT: keep /data/log2 session logs under LOG2_MAX_BYTES total.
+  Deletes oldest dated session directories first (the 'current' symlink/dir
+  is preserved). Runs even when disk space is fine."""
+  log_base = "/data/log2"
+  if not os.path.isdir(log_base):
+    return
+  dirs = []
+  for entry in sorted(os.listdir(log_base)):
+    if entry == "current":
+      continue
+    path = os.path.join(log_base, entry)
+    if os.path.isdir(path) and not os.path.islink(path):
+      try:
+        size = sum(f.stat().st_size for f in os.scandir(path) if f.is_file())
+      except OSError:
+        size = 0
+      dirs.append((entry, path, size))
+  total = sum(s for _, _, s in dirs)
+  current = os.path.join(log_base, "current")
+  if os.path.isdir(current):
+    try:
+      total += sum(f.stat().st_size for f in os.scandir(current) if f.is_file())
+    except OSError:
+      pass
+  while total > LOG2_MAX_BYTES and dirs:
+    entry, path, size = dirs.pop(0)
+    try:
+      print(f"CLP deleter: deleting log session {path} ({size // 1024 // 1024} MB)",
+            file=sys.stderr, flush=True)
+      shutil.rmtree(path)
+      total -= size
+    except OSError as e:
+      print(f"CLP deleter: issue deleting log {path}: {e}", file=sys.stderr, flush=True)
+
+
 def deleter_thread(exit_event):
   while not exit_event.is_set():
     out_of_bytes = get_available_bytes(default=MIN_BYTES + 1) < MIN_BYTES
     out_of_percent = get_available_percent(default=MIN_PERCENT + 1) < MIN_PERCENT
 
     if out_of_percent or out_of_bytes:
+      # CLEARPILOT: drop oldest dashcam footage first, fall back to log segments
+      if delete_oldest_video():
+        exit_event.wait(.1)
+        continue
+
       dirs = listdir_by_creation(Paths.log_root())
 
       # skip deleting most recent N preserved segments (and their prior segment)
@@ -73,6 +173,8 @@ def deleter_thread(exit_event):
           cloudlog.exception(f"issue deleting {delete_path}")
       exit_event.wait(.1)
     else:
+      # CLEARPILOT: keep /data/log2 quota even when disk space is fine
+      cleanup_log2()
       exit_event.wait(30)