feat(j0.1): squelette projet Flutter + arborescence clean archi

- flutter create --platforms=android --org biz.siteop
- arborescence lib/core/{error,theme,router,di} et lib/features/{locking,playback,podcasts,parental,limits}/{domain,application,data,presentation}
- pubspec.yaml : flutter_riverpod ^2.6.1 (YAGNI — autres paquets aux jalons suivants)
- lib/main.dart : ProviderScope + StorytimeApp (MaterialApp + écran placeholder)
- test/app_boots_test.dart : TDD Red→Green vérifié (flutter test vert, flutter analyze 0 issue)
- README.md : prérequis Flutter 3.41.6 / Dart 3.11.4

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

android/settings.gradle.kts

@@ -0,0 +1,26 @@
+pluginManagement {
+    val flutterSdkPath =
+        run {
+            val properties = java.util.Properties()
+            file("local.properties").inputStream().use { properties.load(it) }
+            val flutterSdkPath = properties.getProperty("flutter.sdk")
+            require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
+            flutterSdkPath
+        }
+
+    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
+
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+plugins {
+    id("dev.flutter.flutter-plugin-loader") version "1.0.0"
+    id("com.android.application") version "8.11.1" apply false
+    id("org.jetbrains.kotlin.android") version "2.2.20" apply false
+}
+
+include(":app")