docs: add BUG-24 (OBD stall reconnect) + GPS replay jitter fix notes

PLAN.md

@@ -2301,6 +2301,13 @@ logged as `BUG-XX` entries in [BUGS.md](./BUGS.md) (BUG-16 onward) and fixed + v
   `app_sql.delete_trips_batch()` + a local `deleted_trip_markers` table keep deleted trips from
   resurrecting on rebuild. Deletion is **local-only** — raw tracking rows are preserved and the
   remote server is never notified (it keeps its archival copy).
+- **BUG-24 (OBD adapter stalls mid-drive) — ✅ FIXED**: `obd_speed()` now counts consecutive
+  null-speed polls and force-closes the connection after ~20s of stale null speed, so the
+  reconnect loop re-handshakes instead of flatlining until the next ignition cycle. Root-caused
+  from trip #8 (2026-08-13): speed 102 → None at 14:14:31, never recovered for the trip.
+- **GPS replay speed jitter — ✅ FIXED**: `route_points` (Pi) + `get_trip_route` (server) now
+  derive GPS speed over a trailing ~30s window instead of a single 5s segment, killing the false
+  150+ km/h spikes. Verified: trip #8 max GPS speed 150+ → 127.8 km/h.
 
 Open items from the drive — fill in as reported:
 - (none clock-related — BUG-17/BUG-18 closed 2026-08-14).