Detect config drift in cached tile providers and replace stale instances

When a user edits a tile type's URL template, max zoom, or API key
without changing IDs, the cached DeflockTileProvider would keep the old
frozen config. Now _getOrCreateProvider() computes a config fingerprint
and replaces the provider when drift is detected.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

test/services/provider_tile_cache_store_test.dart

@@ -359,8 +359,8 @@ void main() {
 
   group('ProviderTileCacheStore eviction', () {
     /// Helper: populate cache with [count] tiles, each [bytesPerTile] bytes.
-    /// Uses small delays between writes so modification times are
-    /// distinguishable for oldest-modified ordering.
+    /// Sets deterministic modification times (1 second apart) so eviction
+    /// ordering is stable across platforms without relying on wall-clock delays.
     Future<void> fillCache(
       ProviderTileCacheStore store, {
       required int count,
@@ -373,14 +373,22 @@ void main() {
         lastModified: null,
         etag: null,
       );
+      final baseTime = DateTime.utc(2026, 1, 1);
       for (var i = 0; i < count; i++) {
         await store.putTile(
           url: 'https://tile.example.com/$prefix$i.png',
           metadata: metadata,
           bytes: bytes,
         );
-        // Small delay so modification times are distinguishable for eviction order
-        await Future<void>.delayed(const Duration(milliseconds: 10));
+        // Set deterministic mtime so eviction order is stable across platforms.
+        final key = ProviderTileCacheStore.keyFor(
+          'https://tile.example.com/$prefix$i.png',
+        );
+        final tileFile = File(p.join(store.cacheDirectory, '$key.tile'));
+        final metaFile = File(p.join(store.cacheDirectory, '$key.meta'));
+        final mtime = baseTime.add(Duration(seconds: i));
+        await tileFile.setLastModified(mtime);
+        await metaFile.setLastModified(mtime);
       }
     }
 

test/widgets/map/tile_layer_manager_test.dart

@@ -6,6 +6,7 @@ import 'package:flutter_map/flutter_map.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mocktail/mocktail.dart';
 
+import 'package:deflockapp/models/tile_provider.dart' as models;
 import 'package:deflockapp/services/deflock_tile_provider.dart';
 import 'package:deflockapp/widgets/map/tile_layer_manager.dart';
 
@@ -419,6 +420,136 @@ void main() {
     });
   });
 
+  group('TileLayerManager config drift detection', () {
+    late TileLayerManager manager;
+
+    setUp(() {
+      manager = TileLayerManager();
+    });
+
+    tearDown(() {
+      manager.dispose();
+    });
+
+    models.TileProvider makeProvider({String? apiKey}) => models.TileProvider(
+          id: 'test_provider',
+          name: 'Test',
+          apiKey: apiKey,
+          tileTypes: [],
+        );
+
+    models.TileType makeTileType({
+      String urlTemplate = 'https://example.com/{z}/{x}/{y}.png',
+      int maxZoom = 18,
+    }) =>
+        models.TileType(
+          id: 'test_tile',
+          name: 'Test',
+          urlTemplate: urlTemplate,
+          attribution: 'Test',
+          maxZoom: maxZoom,
+        );
+
+    test('returns same provider for identical config', () {
+      final provider = makeProvider();
+      final tileType = makeTileType();
+
+      final layer1 = manager.buildTileLayer(
+        selectedProvider: provider,
+        selectedTileType: tileType,
+      ) as TileLayer;
+
+      final layer2 = manager.buildTileLayer(
+        selectedProvider: provider,
+        selectedTileType: tileType,
+      ) as TileLayer;
+
+      expect(
+        identical(layer1.tileProvider, layer2.tileProvider),
+        isTrue,
+        reason: 'Same config should return the cached provider instance',
+      );
+    });
+
+    test('replaces provider when urlTemplate changes', () {
+      final provider = makeProvider();
+      final tileTypeV1 = makeTileType(
+        urlTemplate: 'https://old.example.com/{z}/{x}/{y}.png',
+      );
+      final tileTypeV2 = makeTileType(
+        urlTemplate: 'https://new.example.com/{z}/{x}/{y}.png',
+      );
+
+      final layer1 = manager.buildTileLayer(
+        selectedProvider: provider,
+        selectedTileType: tileTypeV1,
+      ) as TileLayer;
+
+      final layer2 = manager.buildTileLayer(
+        selectedProvider: provider,
+        selectedTileType: tileTypeV2,
+      ) as TileLayer;
+
+      expect(
+        identical(layer1.tileProvider, layer2.tileProvider),
+        isFalse,
+        reason: 'Changed urlTemplate should create a new provider',
+      );
+      expect(
+        (layer2.tileProvider as DeflockTileProvider).tileType.urlTemplate,
+        'https://new.example.com/{z}/{x}/{y}.png',
+      );
+    });
+
+    test('replaces provider when apiKey changes', () {
+      final providerV1 = makeProvider(apiKey: 'old_key');
+      final providerV2 = makeProvider(apiKey: 'new_key');
+      final tileType = makeTileType();
+
+      final layer1 = manager.buildTileLayer(
+        selectedProvider: providerV1,
+        selectedTileType: tileType,
+      ) as TileLayer;
+
+      final layer2 = manager.buildTileLayer(
+        selectedProvider: providerV2,
+        selectedTileType: tileType,
+      ) as TileLayer;
+
+      expect(
+        identical(layer1.tileProvider, layer2.tileProvider),
+        isFalse,
+        reason: 'Changed apiKey should create a new provider',
+      );
+      expect(
+        (layer2.tileProvider as DeflockTileProvider).apiKey,
+        'new_key',
+      );
+    });
+
+    test('replaces provider when maxZoom changes', () {
+      final provider = makeProvider();
+      final tileTypeV1 = makeTileType(maxZoom: 18);
+      final tileTypeV2 = makeTileType(maxZoom: 20);
+
+      final layer1 = manager.buildTileLayer(
+        selectedProvider: provider,
+        selectedTileType: tileTypeV1,
+      ) as TileLayer;
+
+      final layer2 = manager.buildTileLayer(
+        selectedProvider: provider,
+        selectedTileType: tileTypeV2,
+      ) as TileLayer;
+
+      expect(
+        identical(layer1.tileProvider, layer2.tileProvider),
+        isFalse,
+        reason: 'Changed maxZoom should create a new provider',
+      );
+    });
+  });
+
   group('TileLayerManager error-type filtering', () {
     late TileLayerManager manager;
     late MockTileImage mockTile;