feat(bibliotheque): tags de filtrage et duplication rapide côté UI (ticket #83)

Lot frontend F1+F2 : composant library_tags.dart (filtre/suggestions de tags), intégration dans exercise_library_screen, program_screen et workout_template_screen (tags + action duplication rapide), tests associés.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/presentation/exercise_library_screen.dart

@@ -6,6 +6,7 @@ import 'package:image_picker/image_picker.dart';
 import '../application/application.dart';
 import '../domain/domain.dart';
 import 'example_badge.dart';
+import 'library_tags.dart';
 import 'theme.dart';
 
 abstract interface class MediaSourcePicker {
@@ -43,6 +44,7 @@ final class ExerciseLibraryScreen extends StatefulWidget {
 final class _ExerciseLibraryScreenState extends State<ExerciseLibraryScreen> {
   final _searchController = TextEditingController();
   var _selectedMeasures = <WorkoutMeasure>{};
+  var _selectedTags = <String>{};
   late Future<List<Exercise>> _exercises;
 
   @override
@@ -82,6 +84,10 @@ final class _ExerciseLibraryScreenState extends State<ExerciseLibraryScreen> {
           }
 
           final exercises = snapshot.data ?? const <Exercise>[];
+          final tagSuggestions = tagSuggestionsFor(
+            exercises,
+            (exercise) => exercise.tags,
+          ).map((usage) => usage.tag).toList();
           final filtered = _filter(exercises);
           return RefreshIndicator(
             onRefresh: () {
@@ -127,6 +133,21 @@ final class _ExerciseLibraryScreenState extends State<ExerciseLibraryScreen> {
                             );
                           }).toList(),
                         ),
+                        if (tagSuggestions.isNotEmpty) ...[
+                          const SizedBox(height: 12),
+                          LibraryTagFilters(
+                            suggestions: tagSuggestions,
+                            selectedTags: _selectedTags,
+                            onToggle: _toggleTag,
+                          ),
+                        ],
+                        if (_filtersActive) ...[
+                          const SizedBox(height: 8),
+                          TextButton(
+                            onPressed: _clearFilters,
+                            child: const Text('Effacer les filtres'),
+                          ),
+                        ],
                       ],
                     ),
                   ),
@@ -143,12 +164,14 @@ final class _ExerciseLibraryScreenState extends State<ExerciseLibraryScreen> {
                     ),
                   )
                 else if (filtered.isEmpty)
-                  const SliverFillRemaining(
+                  SliverFillRemaining(
                     hasScrollBody: false,
                     child: _CenteredMessage(
                       title: 'Aucun exercice ne correspond',
                       message:
-                          'Modifie la recherche ou les filtres de mesures.',
+                          'Modifie la recherche, les mesures ou les tags sélectionnés.',
+                      actionLabel: 'Effacer les filtres',
+                      onAction: _clearFilters,
                     ),
                   )
                 else
@@ -175,7 +198,7 @@ final class _ExerciseLibraryScreenState extends State<ExerciseLibraryScreen> {
 
   List<Exercise> _filter(List<Exercise> exercises) {
     final query = _searchController.text.trim().toLowerCase();
-    return exercises.where((exercise) {
+    final matchingQueryAndMeasures = exercises.where((exercise) {
       final matchesQuery =
           query.isEmpty ||
           exercise.name.toLowerCase().contains(query) ||
@@ -185,6 +208,35 @@ final class _ExerciseLibraryScreenState extends State<ExerciseLibraryScreen> {
           _selectedMeasures.every(exercise.availableMeasures.contains);
       return matchesQuery && matchesMeasures;
     }).toList();
+    return filterByRequiredTags(
+      matchingQueryAndMeasures,
+      _selectedTags,
+      (exercise) => exercise.tags,
+    );
+  }
+
+  bool get _filtersActive {
+    return _searchController.text.trim().isNotEmpty ||
+        _selectedMeasures.isNotEmpty ||
+        _selectedTags.isNotEmpty;
+  }
+
+  void _toggleTag(String tag) {
+    setState(() {
+      if (_selectedTags.contains(tag)) {
+        _selectedTags = {..._selectedTags}..remove(tag);
+      } else {
+        _selectedTags = {..._selectedTags, tag};
+      }
+    });
+  }
+
+  void _clearFilters() {
+    setState(() {
+      _searchController.clear();
+      _selectedMeasures = {};
+      _selectedTags = {};
+    });
   }
 
   void _reload() {
@@ -194,12 +246,18 @@ final class _ExerciseLibraryScreenState extends State<ExerciseLibraryScreen> {
   }
 
   Future<void> _openForm({Exercise? exercise}) async {
+    final exercises = await _exercises;
+    if (!mounted) return;
     final changed = await Navigator.of(context).push<bool>(
       MaterialPageRoute(
         builder: (context) => ExerciseFormScreen(
           exerciseUseCases: widget.exerciseUseCases,
           mediaUseCases: widget.mediaUseCases,
           exercise: exercise,
+          tagSuggestions: tagSuggestionsFor(
+            exercises,
+            (exercise) => exercise.tags,
+          ).map((usage) => usage.tag).toList(),
         ),
       ),
     );
@@ -311,6 +369,9 @@ final class ExerciseListTile extends StatelessWidget {
                   scoreInputMode: exercise.scoreInputMode,
                 ),
               ),
+              ...exercise.tags.take(3).map((tag) => TagChip(label: tag)),
+              if (exercise.tags.length > 3)
+                TagChip(label: '+${exercise.tags.length - 3}'),
               if (hasMedia)
                 const Tooltip(
                   message: 'Média associé',
@@ -393,6 +454,7 @@ final class ExerciseFormScreen extends StatefulWidget {
     required this.mediaUseCases,
     this.mediaPicker = const ImagePickerMediaSourcePicker(),
     this.exercise,
+    this.tagSuggestions = const [],
     super.key,
   });
 
@@ -400,6 +462,7 @@ final class ExerciseFormScreen extends StatefulWidget {
   final MediaUseCases mediaUseCases;
   final MediaSourcePicker mediaPicker;
   final Exercise? exercise;
+  final List<String> tagSuggestions;
 
   @override
   State<ExerciseFormScreen> createState() => _ExerciseFormScreenState();
@@ -430,6 +493,7 @@ final class _ExerciseFormScreenState extends State<ExerciseFormScreen> {
   var _stepsEnabled = false;
   var _autoStartNextTimedStep = true;
   final _stepDrafts = <_ExerciseStepDraft>[];
+  late List<String> _tags;
   String? _measureError;
   String? _stepError;
   String? _warning;
@@ -467,6 +531,7 @@ final class _ExerciseFormScreenState extends State<ExerciseFormScreen> {
     _scoreInputMode = exercise?.scoreInputMode ?? ScoreInputMode.manual;
     _stepsEnabled = exercise?.steps.isNotEmpty ?? false;
     _autoStartNextTimedStep = exercise?.autoStartNextTimedStep ?? true;
+    _tags = List<String>.of(exercise?.tags ?? const []);
     for (final step in exercise?.steps ?? const <ExerciseStep>[]) {
       _stepDrafts.add(_draftFromStep(step));
     }
@@ -515,6 +580,14 @@ final class _ExerciseFormScreenState extends State<ExerciseFormScreen> {
               maxLines: 4,
             ),
             const SizedBox(height: 24),
+            EditableTagsSection(
+              tags: _tags,
+              suggestions: widget.tagSuggestions,
+              description:
+                  'Ajoute quelques mots pour retrouver cet exercice plus vite.',
+              onChanged: (tags) => setState(() => _tags = tags),
+            ),
+            const SizedBox(height: 24),
             Text(
               'Média optionnel',
               style: Theme.of(context).textTheme.titleMedium,
@@ -1358,6 +1431,7 @@ final class _ExerciseFormScreenState extends State<ExerciseFormScreen> {
           defaultTargetScoreTimeMs: defaultTargetScoreTimeMs,
           autoStartNextTimedStep: _autoStartNextTimedStep,
           steps: steps,
+          tags: _tags,
         );
       } else {
         await widget.exerciseUseCases.update(
@@ -1379,6 +1453,7 @@ final class _ExerciseFormScreenState extends State<ExerciseFormScreen> {
           defaultTargetScoreTimeMs: defaultTargetScoreTimeMs,
           autoStartNextTimedStep: _autoStartNextTimedStep,
           steps: steps,
+          tags: _tags,
         );
       }
       if (mounted) {