feat(mobile): Expo → RN CLI 전환 + Android 빌드 성공

RN 0.85 + React 19 기반 apps/mobile-rn 프로젝트 생성.
6개 화면 이식 (Login, Dash, History, Record, Talk, Settings).
@react-navigation/native + bottom-tabs 네비게이션 구성.
Windows NDK CMake libc++_shared 링크 버그 워크아라운드 포함.
Galaxy Fold (SM_F956N) 무선 디버깅 APK 설치 확인.

apps/mobile-rn/android/build.gradle

@@ -0,0 +1,21 @@
+buildscript {
+    ext {
+        buildToolsVersion = "36.0.0"
+        minSdkVersion = 24
+        compileSdkVersion = 36
+        targetSdkVersion = 36
+        ndkVersion = "27.1.12297006"
+        kotlinVersion = "2.1.20"
+    }
+    repositories {
+        google()
+        mavenCentral()
+    }
+    dependencies {
+        classpath("com.android.tools.build:gradle")
+        classpath("com.facebook.react:react-native-gradle-plugin")
+        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin")
+    }
+}
+
+apply plugin: "com.facebook.react.rootproject"