feat: picture in picture

- 移除了 MainScreen 中的全屏方向处理及相关状态管理
- 引入 AppRuntime 用于管理跨 Activity 的共享实例
- 创建 StreamScreen 用于画中画模式
- 实现 VideoOutputTarget 和 VideoOutputTargetState 以管理视频输出状态

gradle/libs.versions.toml

@@ -12,6 +12,7 @@ espressoCore = "3.7.0"
 miuix = "0.9.0"
 material = "1.13.0"
 runtime = "1.10.5"
+androidxCorePip = "1.0.0-alpha02"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -36,6 +37,7 @@ miuix-preference = { group = "top.yukonga.miuix.kmp", name = "miuix-preference",
 miuix-icons = { group = "top.yukonga.miuix.kmp", name = "miuix-icons", version.ref = "miuix" }
 miuix-navigation3-ui = { group = "top.yukonga.miuix.kmp", name = "miuix-navigation3-ui", version.ref = "miuix" }
 androidx-compose-runtime = { group = "androidx.compose.runtime", name = "runtime", version.ref = "runtime" }
+androidx-core-pip = { group = "androidx.core", name = "core-pip", version.ref = "androidxCorePip" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }