backlog: refine foresight live activity notes

BACKLOG.md

@@ -149,10 +149,15 @@ Status: TODO / IN PROGRESS / DONE / BLOCKED.
   from cached data only (no extra source-data refresh on motion). Best v1 shape:
   Live Activity option, not widget-first, because widget space/refresh budgets
   are tight and the lock-screen/CarPlay compact slot better matches the use case.
-  Viable MVP: infer heading from recent motion/course, keep only stations in a
-  forward cone, score candidates by forward distance + lateral offset, and show
-  the next-ahead station with all three fuel prices or a compact rotating/focused
-  fuel treatment if space allows. Key caveat: heading is not full route awareness,
+  Prefer ONE FuelBoard Live Activity with a mode selector (e.g. `Nearby cheapest`
+  vs `Foresight / next ahead`) rather than trying to run two simultaneous
+  FuelBoard activities; iOS can support multiple activities, but FuelBoard's
+  current implementation is single-activity and the compact surfaces are too
+  constrained for two competing driving modes anyway. Viable MVP: infer heading
+  from recent motion/course, keep only stations in a forward cone, score
+  candidates by forward distance + lateral offset, and show the next-ahead
+  station with all three fuel prices or a compact rotating/focused fuel
+  treatment if space allows. Key caveat: heading is not full route awareness,
   so avoid overpromising "the next station you will reach" on motorways/opposite
   carriageways; frame as "next ahead" / "likely next stop" unless route-quality
   heuristics improve. Must include hysteresis/speed thresholds to avoid flapping,