feat(app): scaffolding initial du projet Flutter GameTime

Structure Flutter iOS/Android (lib/ organisé en couches domain,
application, infrastructure, presentation), intégration Drift pour la
persistance locale (sqlite3_flutter_libs), configuration des plateformes
android/ et ios/. Build APK debug validé.

Ajuste le .gitignore pour ignorer l'état d'exécution IdeA
(.ideai/permissions.json) au même titre que le reste du runtime.

Co-Authored-By: Claude Opus 4.8 <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 "9.0.1" apply false
+    id("org.jetbrains.kotlin.android") version "2.3.20" apply false
+}
+
+include(":app")