V3-04: live map on the recording screen

Feeds RideMap from watchPointsForTrip/watchSegmentsForTrip via autoDispose.family providers. RecordingEngine stays map-free (enforced by architecture_test.dart). RideMap gained lifecycle-aware tile teardown and follow-mode, both shared with the trip-detail map.

test/architecture_test.dart

@@ -0,0 +1,15 @@
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+
+/// A structural invariant from V3-04, checked directly rather than trusted: rendering
+/// belongs to a visible screen's widget lifecycle, never to the recording engine. If this
+/// ever starts failing, a map reference has leaked into code that keeps running while the
+/// phone is pocketed and the screen is off.
+void main() {
+  test('RecordingEngine never imports the map', () {
+    final source = File('lib/src/recording/recording_engine.dart').readAsStringSync();
+    expect(source.contains('ride_map'), isFalse);
+    expect(source.contains('flutter_map'), isFalse);
+  });
+}

test/widget_test.dart

@@ -1,6 +1,8 @@
 import 'package:drift/drift.dart' show driftRuntimeOptions;
 import 'package:drift/native.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_map/flutter_map.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:rippr/src/app/providers.dart';
@@ -137,7 +139,7 @@ void main() {
     screenTest('recording swaps to PAUSE and STOP, with no DISCARD',
         (tester) async {
       await repo.startTrip(1000);
-      await pumpLive(tester, host(const RecordScreen()));
+      await pumpLive(tester, host(const RecordScreen(), map: false));
 
       expect(find.byKey(const Key('pause')), findsOneWidget);
       expect(find.byKey(const Key('stop')), findsOneWidget);
@@ -150,7 +152,7 @@ void main() {
     screenTest('paused offers RESUME, STOP and DISCARD', (tester) async {
       await repo.startTrip(1000);
       await repo.pauseTrip(2000);
-      await pumpLive(tester, host(const RecordScreen()));
+      await pumpLive(tester, host(const RecordScreen(), map: false));
 
       expect(find.byKey(const Key('resume')), findsOneWidget);
       expect(find.byKey(const Key('stop')), findsOneWidget);
@@ -161,7 +163,7 @@ void main() {
     screenTest('discard asks before destroying anything', (tester) async {
       await repo.startTrip(1000);
       await repo.pauseTrip(2000);
-      await pumpLive(tester, host(const RecordScreen()));
+      await pumpLive(tester, host(const RecordScreen(), map: false));
 
       await tester.tap(find.byKey(const Key('discard')));
       await tester.pumpAndSettle();
@@ -208,6 +210,66 @@ void main() {
       expect(opened, isTrue,
           reason: 'the button must actually invoke the callback that navigates');
     });
+
+    screenTest('the live map appears only while recording and the toggle is on '
+        '(V3-04)', (tester) async {
+      // Idle, toggle on: no trip to draw, so no map at all.
+      await tester.pumpWidget(host(const RecordScreen()));
+      await tester.pumpAndSettle();
+      expect(find.byKey(const Key('live-map')), findsNothing);
+
+      // Recording, toggle off: RecordingEngine has produced a trip, but the map must
+      // not be constructed at all -- not just hidden.
+      await repo.startTrip(1000);
+      await tester.pumpWidget(const SizedBox.shrink());
+      await pumpLive(tester, host(const RecordScreen(), map: false));
+      expect(find.byKey(const Key('live-map')), findsNothing);
+      expect(find.byType(FlutterMap), findsNothing);
+
+      // Recording, toggle on: the map is drawn.
+      await tester.pumpWidget(const SizedBox.shrink());
+      await pumpLive(tester, host(const RecordScreen()));
+      expect(find.byKey(const Key('live-map')), findsOneWidget);
+    });
+
+    screenTest('backgrounding the app drops the tile layer (V3-04)',
+        (tester) async {
+      final h = await repo.startTrip(1000);
+      await repo.appendPoints([
+        TrackPoint(
+          tripId: h.tripId,
+          segmentId: h.segmentId,
+          timestamp: 1000,
+          latitude: 51.0,
+          longitude: -114.0,
+          speedKmh: 20.0,
+          altitudeM: 1000.0,
+        ),
+      ]);
+      await pumpLive(tester, host(const RecordScreen()));
+
+      expect(find.byType(TileLayer), findsOneWidget,
+          reason: 'foregrounded: tiles render normally');
+
+      // Simulates the platform lifecycle message a real backgrounding sends -- this is
+      // the standard way to drive AppLifecycleState changes in a widget test.
+      final message = const StringCodec().encodeMessage('AppLifecycleState.paused');
+      await tester.binding.defaultBinaryMessenger
+          .handlePlatformMessage('flutter/lifecycle', message, (_) {});
+      await tester.pump();
+
+      expect(find.byType(TileLayer), findsNothing,
+          reason: 'backgrounded: no tile layer means no tile request can fire');
+      expect(find.byType(PolylineLayer), findsOneWidget,
+          reason: 'the drawn path itself is not removed, only tile fetching');
+
+      final resumed = const StringCodec().encodeMessage('AppLifecycleState.resumed');
+      await tester.binding.defaultBinaryMessenger
+          .handlePlatformMessage('flutter/lifecycle', resumed, (_) {});
+      await tester.pump();
+      expect(find.byType(TileLayer), findsOneWidget,
+          reason: 'foregrounding again must resume tiles');
+    });
   });
 
   group('trips list', () {