obd-poller done (mode 01); DTC/MUT-III and first decoding captures next

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

docs/ROADMAP.md

@@ -59,7 +59,13 @@ mark …`, or the app's Mark button), on the same clock as the frames.
       `docs/impl/reports/Z27AG-CAN-PRIOR-ART.md`
 - [ ] Build the Z27AG DBC incrementally in `contracts`
 - [ ] `decoder` — raw frames to named signals
-- [ ] `obd-poller` — active OBD-II PIDs, single writer, rate-limited
+- [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`)
+- [ ] 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`
 - [ ] `gnss` — position/speed, useful as ground truth for validating decoded speed
 
 OBD-II gives standardised signals quickly and is worth doing early; it also