dashcam: re-enable screen recorder, disable training data video

- Re-enable FrogPilot OMX screen recorder (H.264 MP4, 1440x720, 2Mbps)
- Auto-start recording when car is on, auto-stop when off
- Hide all recorder UI elements (invisible to driver)
- Add ScreenRecorderDebug param for bench testing without car
- Disable encoderd (camera .hevc files) — CAN/sensor logs still recorded
- Raise deleter free space threshold from 5GB to 9GB
- Deleter rotates oldest videos before log segments
- Add CLAUDE.md project documentation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

selfdrive/manager/manager.py

@@ -229,6 +229,7 @@ def manager_init(frogpilot_functions) -> None:
     ("ScreenBrightnessOnroad", "101"),
     ("ScreenManagement", "1"),
     ("ScreenRecorder", "1"),
+    ("ScreenRecorderDebug", "1"),
     ("ScreenTimeout", "30"),
     ("ScreenTimeoutOnroad", "30"),
     ("SearchInput", "0"),