feat: MVP implementation - Kiosk Browser

- Fullscreen WebView with immersive mode
- URL whitelist system
- Admin PIN-protected settings
- Boot receiver for auto-launch
- Idle timeout with homepage reset
- Lock Task Mode support
- Material Design 3 UI

Team: Pluto (coordinator), Margaret, Spirit

settings.gradle.kts

@@ -0,0 +1,17 @@
+pluginManagement {
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+rootProject.name = "KioskBrowser"
+include(":app")