V3-06: live stats in the notification

RideNotificationController seam over flutter_local_notifications; RideNotificationCoordinator wires TripRepository.watchActiveTrip() to it and routes Pause/Resume actions back into RecordingEngine. Instantiated eagerly at app root rather than screen-owned, since a pocketed ride has no visible widget tree. Documents an unresolved risk: geolocator's own foreground-service notification cannot be suppressed, so two notifications may be visible until verified on a device.

lib/main.dart

@@ -33,10 +33,15 @@ class _RipprAppState extends ConsumerState<RipprApp> {
   }
 
   @override
-  Widget build(BuildContext context) => MaterialApp.router(
-    title: 'Rippr',
-    debugShowCheckedModeBanner: false,
-    theme: ripprTheme(),
-    routerConfig: _router,
-  );
+  Widget build(BuildContext context) {
+    // V3-06: forces creation so the live notification keeps updating and Pause/Resume
+    // keeps working regardless of which screen is on top -- see the provider's doc.
+    ref.watch(rideNotificationCoordinatorProvider);
+    return MaterialApp.router(
+      title: 'Rippr',
+      debugShowCheckedModeBanner: false,
+      theme: ripprTheme(),
+      routerConfig: _router,
+    );
+  }
 }