svc-vision: new repo for the camera; decision 29 (Python for vision)

The live view moved from app-flutter's test tool to svc-vision, running as
yukart-vision.service on the car Orin.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DDwfd6Ki8UfG4hK6W5YpJz

docs/ROADMAP.md

@@ -1,7 +1,7 @@
 ---
 type: plan
 status: active
-updated: 2026-10-11
+updated: 2026-10-12
 ---
 # Roadmap
 
@@ -97,12 +97,14 @@ cores at 1080p; frame rate falls with the light.
       tablet, inference input, or several
 - [ ] Measure in the car: daylight and night frame rate and MJPEG size on a road
       scene
-- [ ] One capture process owns `/dev/video0` (V4L2 is single-reader) and feeds
+- [ ] One capture process owns the camera (V4L2 is single-reader) and feeds
       the others; sets UVC controls on open, since they reset on re-enumeration
 - [ ] Recording: H.264 segments on the recorder's clock and session marks,
       bounded like CAN sessions (~2.7 GB per hour at 6 Mbit/s)
-- [ ] Live view in `app-flutter` (decision 27, proposed): 720p MJPEG passthrough
-      (~3.4 MB/s, no CPU) or H.264, paced per decision 28
+- [x] Live view (decision 27, proposed), 2026-10-12: `svc-vision` serves 720p
+      MJPEG passthrough on `:7710` (`yukart-vision.service`, ~2% of a core),
+      paced per decision 28, camera-agnostic, says when there is no camera;
+      `app-flutter` shows it with exposure and gain controls
 - [ ] Inference — deferred; plan for evicting voice, not for coexisting with it
       ([ORIN-RUNTIME.md](ORIN-RUNTIME.md))