feat(bibliotheque): tags et duplication profonde

Ticket #83 B1-B3 : tags JSON dénormalisés, migration Drift v19, mappings sync, helpers de filtre/suggestions, duplication profonde Program/WorkoutTemplate, tests associés.

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

lib/infrastructure/local/drift_repositories.dart

@@ -2816,6 +2816,7 @@ db.ExercisesCompanion _exerciseCompanion(domain.Exercise exercise) {
     defaultTargetScore: Value(exercise.defaultTargetScore),
     defaultTargetScoreTimeMs: Value(exercise.defaultTargetScoreTimeMs),
     autoStartNextTimedStep: Value(exercise.autoStartNextTimedStep),
+    tagsJson: Value(_encodeTags(exercise.tags)),
     archivedAt: Value(_utcOrNull(exercise.archivedAt)),
   );
 }
@@ -2846,6 +2847,7 @@ domain.Exercise _exerciseFromRow(
     autoStartNextTimedStep: row.autoStartNextTimedStep,
     category: starterMetadata.category,
     isExample: starterMetadata.isExample,
+    tags: _decodeTags(row.tagsJson),
     steps: steps,
     archivedAt: _utcOrNull(row.archivedAt),
   );
@@ -3028,6 +3030,7 @@ db.ProgramsCompanion _programCompanion(domain.Program program) {
     remoteRevision: values[10] as Value<String?>,
     name: Value(program.name),
     defaultRestSeconds: Value(program.defaultRestSeconds),
+    tagsJson: Value(_encodeTags(program.tags)),
   );
 }
 
@@ -3041,6 +3044,7 @@ domain.Program _programFromRow(
     name: row.name,
     defaultRestSeconds: row.defaultRestSeconds,
     isExample: isExample,
+    tags: _decodeTags(row.tagsJson),
     exercises: exercises,
   );
 }
@@ -3157,6 +3161,7 @@ db.WorkoutTemplatesCompanion _workoutTemplateCompanion(
     remoteRevision: values[10] as Value<String?>,
     name: Value(template.name),
     lastStartedAt: Value(_utcOrNull(template.lastStartedAt)),
+    tagsJson: Value(_encodeTags(template.tags)),
   );
 }
 
@@ -3171,6 +3176,7 @@ domain.WorkoutTemplate _workoutTemplateFromRow(
     name: row.name,
     lastStartedAt: _utcOrNull(row.lastStartedAt),
     isExample: isExample,
+    tags: _decodeTags(row.tagsJson),
     programs: programs,
     overrides: overrides,
   );
@@ -4077,6 +4083,7 @@ Map<String, Object?> _exercisePayload(domain.Exercise exercise) => {
   'autoStartNextTimedStep': exercise.autoStartNextTimedStep,
   'category': exercise.category.name,
   'isExample': exercise.isExample,
+  'tags': exercise.tags,
   'steps': exercise.steps.map((step) => step.toSnapshotJson()).toList(),
   'archivedAt': exercise.archivedAt?.toUtc().toIso8601String(),
 };
@@ -4102,6 +4109,7 @@ Map<String, Object?> _programPayload(domain.Program program) => {
   'name': program.name,
   'defaultRestSeconds': program.defaultRestSeconds,
   'isExample': program.isExample,
+  'tags': program.tags,
   'exercises': program.exercises
       .map((exercise) => exercise.toSnapshotJson())
       .toList(),
@@ -4114,6 +4122,7 @@ Map<String, Object?> _workoutTemplatePayload(domain.WorkoutTemplate template) =>
       'name': template.name,
       'lastStartedAt': template.lastStartedAt?.toUtc().toIso8601String(),
       'isExample': template.isExample,
+      'tags': template.tags,
       'programs': template.programs
           .map(
             (program) => {
@@ -4183,6 +4192,7 @@ domain.Exercise _exerciseFromPayload(RemoteSyncedItem item) {
       payload['category'] as String? ?? 'uncategorized',
     ),
     isExample: payload['isExample'] as bool? ?? false,
+    tags: _stringListFromPayload(payload['tags']),
     steps: _stepsFromPayload(payload['steps']),
     archivedAt: _dateTimeFromPayload(payload['archivedAt']),
   );
@@ -4213,6 +4223,7 @@ domain.Program _programFromPayload(RemoteSyncedItem item) {
     name: _stringFromPayload(payload, 'name', item.clientId),
     defaultRestSeconds: payload['defaultRestSeconds'] as int? ?? 0,
     isExample: payload['isExample'] as bool? ?? false,
+    tags: _stringListFromPayload(payload['tags']),
     exercises: _programExercisesFromPayload(payload['exercises'], metadata),
   );
 }
@@ -4225,6 +4236,7 @@ domain.WorkoutTemplate _workoutTemplateFromPayload(RemoteSyncedItem item) {
     name: _stringFromPayload(payload, 'name', item.clientId),
     lastStartedAt: _dateTimeFromPayload(payload['lastStartedAt']),
     isExample: payload['isExample'] as bool? ?? false,
+    tags: _stringListFromPayload(payload['tags']),
     programs: _workoutTemplateProgramsFromPayload(
       payload['programs'],
       metadata,
@@ -4422,6 +4434,23 @@ List<String> _stringListFromPayload(Object? value) {
   return value.whereType<String>().toList(growable: false);
 }
 
+String _encodeTags(List<String> tags) => jsonEncode(domain.normalizeTags(tags));
+
+List<String> _decodeTags(String? encoded) {
+  if (encoded == null || encoded.trim().isEmpty) {
+    return const [];
+  }
+  try {
+    final decoded = jsonDecode(encoded);
+    if (decoded is! List) {
+      return const [];
+    }
+    return domain.normalizeTags(decoded.whereType<String>());
+  } on Object {
+    return const [];
+  }
+}
+
 List<domain.ExerciseStep> _stepsFromPayload(Object? value) {
   if (value is! List) {
     return const [];