feat(android): 设置持久化（推流参数与连接信息）

app/src/main/java/com/opendance/studio/data/AppSettings.kt

@@ -0,0 +1,94 @@
+package com.opendance.studio.data
+
+import android.content.Context
+import androidx.core.content.edit
+
+/**
+ * 应用设置（SharedPreferences）。
+ *
+ * 契约 websocket-keypoints.md §3.3 的 config 字段与这里的前四项一一对应。
+ */
+class AppSettings(context: Context) {
+
+    private val prefs = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
+
+    /** Windows 客户端主机地址 */
+    var host: String
+        get() = prefs.getString(KEY_HOST, DEFAULT_HOST) ?: DEFAULT_HOST
+        set(value) = prefs.edit { putString(KEY_HOST, value.trim()) }
+
+    var port: Int
+        get() = prefs.getInt(KEY_PORT, DEFAULT_PORT)
+        set(value) = prefs.edit { putInt(KEY_PORT, value.coerceIn(1, 65535)) }
+
+    /** 目标帧率（契约 config.targetFps） */
+    var targetFps: Int
+        get() = prefs.getInt(KEY_TARGET_FPS, DEFAULT_FPS)
+        set(value) = prefs.edit { putInt(KEY_TARGET_FPS, value.coerceIn(5, 60)) }
+
+    /** 是否镜像画面（契约 flags.bit0 / config.mirror） */
+    var mirror: Boolean
+        get() = prefs.getBoolean(KEY_MIRROR, true)
+        set(value) = prefs.edit { putBoolean(KEY_MIRROR, value) }
+
+    /** 仅上半身模式（契约 flags.bit2） */
+    var upperBodyOnly: Boolean
+        get() = prefs.getBoolean(KEY_UPPER_BODY, false)
+        set(value) = prefs.edit { putBoolean(KEY_UPPER_BODY, value) }
+
+    /** 分辨率档位，取值见 [Resolutions] */
+    var resolution: String
+        get() = prefs.getString(KEY_RESOLUTION, Resolutions.MEDIUM) ?: Resolutions.MEDIUM
+        set(value) = prefs.edit { putString(KEY_RESOLUTION, value) }
+
+    /** 上次连接的设备名（hello 上报用） */
+    var deviceLabel: String
+        get() = prefs.getString(KEY_DEVICE_LABEL, "") ?: ""
+        set(value) = prefs.edit { putString(KEY_DEVICE_LABEL, value) }
+
+    /** 自动重连 */
+    var autoReconnect: Boolean
+        get() = prefs.getBoolean(KEY_AUTO_RECONNECT, true)
+        set(value) = prefs.edit { putBoolean(KEY_AUTO_RECONNECT, value) }
+
+    fun webSocketUrl(): String = "ws://$host:$port/pose"
+
+    companion object {
+        const val PREFS_NAME = "opendance_settings"
+        const val DEFAULT_HOST = "192.168.1.100"
+        const val DEFAULT_PORT = 8765
+        const val DEFAULT_FPS = 30
+
+        private const val KEY_HOST = "host"
+        private const val KEY_PORT = "port"
+        private const val KEY_TARGET_FPS = "target_fps"
+        private const val KEY_MIRROR = "mirror"
+        private const val KEY_UPPER_BODY = "upper_body_only"
+        private const val KEY_RESOLUTION = "resolution"
+        private const val KEY_DEVICE_LABEL = "device_label"
+        private const val KEY_AUTO_RECONNECT = "auto_reconnect"
+    }
+}
+
+/** 分辨率档位 —— 与契约 config.resolution 的取值格式一致 */
+object Resolutions {
+    const val LOW = "480x360"
+    const val MEDIUM = "640x480"
+    const val HIGH = "1280x720"
+
+    val ALL = listOf(LOW, MEDIUM, HIGH)
+
+    /** 返回 (宽, 高) */
+    fun parse(value: String): Pair<Int, Int> {
+        val parts = value.split("x")
+        val w = parts.getOrNull(0)?.toIntOrNull() ?: 640
+        val h = parts.getOrNull(1)?.toIntOrNull() ?: 480
+        return w to h
+    }
+
+    fun label(value: String): String = when (value) {
+        LOW -> "低（480×360，最省电）"
+        HIGH -> "高（1280×720，最清晰）"
+        else -> "中（640×480，推荐）"
+    }
+}