feat(android): implement secure self-hosted companion and release builds

Add native HTTPS onboarding, origin-bound WebView, isolated web authentication, persistent sessions, upload/camera picker, bounded authenticated downloads and recovery. Validate JVM policy tests, debug APK, lint and unsigned release APK/AAB. Build outputs can be relocated for WSL.

android/settings.gradle.kts

@@ -0,0 +1,7 @@
+pluginManagement { repositories { google(); mavenCentral(); gradlePluginPortal() } }
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories { google(); mavenCentral() }
+}
+rootProject.name = "YuvomiMobile"
+include(":app")