fix(gym_mode): prevent LateInitializationError during exercise hydration (#1366)

lib/features/routines/models/set_config_data.dart

@@ -31,8 +31,23 @@ class SetConfigData {
   @JsonKey(required: true, name: 'exercise')
   late int exerciseId;
 
+  Exercise? _exercise;
+
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  Exercise get exercise {
+    if (_exercise == null) {
+      throw StateError(
+        'SetConfigData for slot entry $slotEntryId has no hydrated exercise '
+        '(exercise ID $exerciseId)',
+      );
+    }
+    return _exercise!;
+  }
+
+  set exercise(Exercise value) => _exercise = value;
+
   @JsonKey(includeFromJson: false, includeToJson: false)
-  late Exercise exercise;
+  Exercise? get exerciseOrNull => _exercise;
 
   @JsonKey(required: true, name: 'slot_entry_id')
   late int slotEntryId;
@@ -181,7 +196,7 @@ class SetConfigData {
       restTime: restTime ?? this.restTime,
       maxRestTime: maxRestTime ?? this.maxRestTime,
       comment: comment ?? this.comment,
-      exercise: exercise ?? this.exercise,
+      exercise: exercise ?? _exercise,
       weightUnit: weightUnit ?? this.weightUnit,
       repetitionsUnit: repetitionsUnit ?? this.repetitionsUnit,
     );

lib/features/routines/providers/gym_state_notifier.dart

@@ -173,6 +173,13 @@ class GymStateNotifier extends _$GymStateNotifier {
       }
 
       for (final config in slotData.setConfigs) {
+        if (config.exerciseOrNull == null) {
+          _logger.warning(
+            'Exercise ${config.exerciseId} not hydrated for slot entry '
+            '${config.slotEntryId}, skipping page.',
+          );
+          continue;
+        }
         // Log page
         slotEntries.add(
           SlotPageEntry(

lib/features/routines/widgets/gym_mode/exercise_overview.dart

@@ -42,7 +42,12 @@ class ExerciseOverview extends ConsumerWidget {
       );
       return Container();
     }
-    final exercise = page.setConfigData!.exercise;
+    final exercise = page.setConfigData!.exerciseOrNull;
+
+    if (exercise == null) {
+      _logger.info('Exercise for slot page $slotUuid not hydrated yet, showing empty container.');
+      return Container();
+    }
 
     return Column(
       children: [

lib/features/routines/widgets/gym_mode/log_page.dart

@@ -73,6 +73,12 @@ class LogPage extends ConsumerWidget {
       return Container();
     }
     final setConfigData = slotEntryPage.setConfigData!;
+    final exercise = setConfigData.exerciseOrNull;
+
+    if (exercise == null) {
+      _logger.info('Exercise for slot page $slotUuid not hydrated yet, showing empty container.');
+      return Container();
+    }
 
     // Past logs come straight from the local DB (not the gym-mode routine
     // snapshot) so a set logged during this workout shows up right away.
@@ -93,7 +99,7 @@ class LogPage extends ConsumerWidget {
     return Column(
       children: [
         NavigationHeader(
-          setConfigData.exercise.getTranslation(languageCode).name,
+          exercise.getTranslation(languageCode).name,
           _controller,
         ),
 
@@ -135,15 +141,15 @@ class LogPage extends ConsumerWidget {
             ),
           ),
         ),
-        if (setConfigData.exercise.showPlateCalculator) const LogsPlatesWidget(),
+        if (exercise.showPlateCalculator) const LogsPlatesWidget(),
         if (slotEntryPage.setConfigData!.comment.isNotEmpty)
           Text(slotEntryPage.setConfigData!.comment, textAlign: TextAlign.center),
         const SizedBox(height: 10),
 
         // Overriding the log scope from here is handled in a follow-up, the
         // settings currently only live in the gym mode options.
         // _LogScopeControls(gymState: gymState),
-        Expanded(child: _buildPastLogs(pastLogs, setConfigData.exercise)),
+        Expanded(child: _buildPastLogs(pastLogs, exercise)),
 
         Padding(
           padding: const EdgeInsets.all(10),

lib/features/routines/widgets/gym_mode/start_page.dart

@@ -248,10 +248,12 @@ class StartPage extends ConsumerWidget {
                     ),
                   ),
                 ),
+
               ...dayDataDisplay.slots
                   .expand((slot) => slot.setConfigs)
+                  .where((entry) => entry.exerciseOrNull != null)
                   .fold<Map<Exercise, List<String>>>({}, (acc, entry) {
-                    acc.putIfAbsent(entry.exercise, () => []).add(entry.textReprWithType);
+                    acc.putIfAbsent(entry.exerciseOrNull!, () => []).add(entry.textReprWithType);
                     return acc;
                   })
                   .entries