feat(ui): identité visuelle Court Blazer sur toute l'app (ticket #17)

Ajoute le thème centralisé (presentation/theme.dart) basé sur les
polices Anton/Archivo et l'applique à tous les écrans (accueil,
bibliothèque d'exercices, programme, séance-modèle, exécution de
séance, historique). flutter analyze propre, 27/27 tests verts, build
APK debug validé.

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

lib/presentation/workout_execution_screen.dart

@@ -6,6 +6,7 @@ import 'package:flutter/material.dart';
 import '../application/application.dart';
 import '../domain/domain.dart';
 import 'history_screen.dart';
+import 'theme.dart';
 
 enum WorkoutExecutionMode { active, rest, paused, finished }
 
@@ -146,7 +147,7 @@ final class _WorkoutExecutionScreenState extends State<WorkoutExecutionScreen> {
           Center(
             child: Text(
               _formatDuration(Duration(seconds: _remainingRestSeconds)),
-              style: Theme.of(context).textTheme.displayLarge,
+              style: AppTextStyles.timer(context),
             ),
           ),
           if (next != null && nextExercise != null) ...[
@@ -533,7 +534,7 @@ final class SetMeasureInput extends StatelessWidget {
                     exercise.targetTimeSeconds == null
                         ? 'Chronométrer'
                         : '${exercise.targetTimeSeconds} s',
-                    style: Theme.of(context).textTheme.displaySmall,
+                    style: AppTextStyles.scoreNumber(context),
                   ),
                 ],
               ),
@@ -549,7 +550,7 @@ final class SetMeasureInput extends StatelessWidget {
                     onRepsChanged((reps - 1).clamp(0, 999).toInt()),
                 icon: const Icon(Icons.remove),
               ),
-              Text('$reps'),
+              Text('$reps', style: AppTextStyles.scoreNumber(context)),
               IconButton(
                 onPressed: () => onRepsChanged(reps + 1),
                 icon: const Icon(Icons.add),
@@ -561,11 +562,11 @@ final class SetMeasureInput extends StatelessWidget {
           const SizedBox(height: 12),
           TextField(
             controller: scoreController,
+            style: AppTextStyles.scoreNumber(context),
             decoration: InputDecoration(
               labelText: exercise.scoreUnit == null
                   ? 'Score'
                   : 'Score (${exercise.scoreUnit})',
-              border: const OutlineInputBorder(),
             ),
             keyboardType: TextInputType.number,
           ),
@@ -770,13 +771,16 @@ final class _Header extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return Column(
-      crossAxisAlignment: CrossAxisAlignment.start,
-      children: [
-        Text(elapsedLabel, style: Theme.of(context).textTheme.headlineSmall),
-        const SizedBox(height: 4),
-        Text(progressLabel),
-      ],
+    return CourtBlazerAccentPanel(
+      padding: const EdgeInsets.all(14),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(elapsedLabel, style: AppTextStyles.scoreNumber(context)),
+          const SizedBox(height: 4),
+          Text(progressLabel),
+        ],
+      ),
     );
   }
 }