Feat: Android client Phase 0-3 full implementation

android/app/src/main/java/com/yama/client/YamaBridge.kt

@@ -0,0 +1,26 @@
+package com.yama.client
+
+object YamaBridge {
+    init {
+        System.loadLibrary("yama")
+    }
+
+    external fun nativeInit(
+        serverIp: String,
+        serverPort: Int,
+        androidId: String,
+        deviceModel: String,
+        androidVersion: String,
+        screenRes: String,
+        username: String,
+        apkPath: String
+    ): Int
+
+    external fun nativeStop()
+
+    /** MediaCodec 配置完成后调用，告知 C++ 实际捕获分辨率 */
+    external fun nativeSetScreenSize(width: Int, height: Int)
+
+    /** MediaCodec 每输出一帧 H.264 NALU 时调用 */
+    external fun nativeOnH264Frame(data: ByteArray, offset: Int, size: Int, isKeyframe: Boolean)
+}