Nothing transmits on CAN: the single writer is obd-poller, on the K-line; gnss live

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

docs/ROADMAP.md

@@ -70,14 +70,17 @@ mark …`, or the app's Mark button), on the same clock as the frames.
 - [x] `obd-poller` — active OBD-II PIDs, single writer, 2026-10-12: mode 01, the
       nine `obd2` signals (~10 Hz fast, 1 Hz slow), only while the bus is alive;
       `can_pcan` out of listen-only. Recorded beside the frames (`vehicle.ndjson`).
-      **Disabled 2026-10-13:** the Z27AG doesn't answer OBD-II on CAN (likely
-      K-line, pin 7); kept for later active-send use
+      2026-10-13: the Z27AG answers OBD-II only on the K-line (ISO 9141-2), so the
+      poller now goes through the Bluetooth ELM327 (classic serial, no pairing):
+      the `obd_*` signals, calibration references per decision 30
 - [ ] OBD-II beyond mode 01: DTC scan (modes 03/07/0A) and MUT-III `21 xx`
       requests, both needing multi-frame (ISO-TP) replies
 - [ ] First decoding captures in the car, per contracts
       `docs/impl/plans/Z27AG-CAPTURES.md` — first checklist session 2026-10-13
       (117 marks, yukart-data `can-captures/`); jack-stands section still to do
-- [ ] `gnss` — position/speed, useful as ground truth for validating decoded speed
+- [x] `gnss` — position/speed, useful as ground truth for validating decoded speed,
+      2026-10-13: svc-core `gnss`, the fix as `yukart/gnss/<signal>` (speed, heading,
+      position, altitude, satellites); `yukart/gnss/fix` for navigation still to come
 
 OBD-II gives standardised signals quickly and is worth doing early; it also
 provides a cross-check for reverse-engineered ones.