fix: 支持明文网络请求，增强安装脚本自动卸载冲突签名，优化设置页AI配置响应

kouyu_english/android/app/src/main/AndroidManifest.xml

@@ -2,6 +2,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.RECORD_AUDIO" />
     <application
+        android:usesCleartextTraffic="true"
         android:label="kouyu_english"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">

kouyu_english/install_app.sh

@@ -23,9 +23,13 @@ if [ ! -f "$APK_PATH" ]; then
 fi
 
 echo "🚀 正在安装 APK 到手机..."
+if ! adb install -r "$APK_PATH"; then
+  echo "⚠️ 覆盖安装失败（签名不一致或版本冲突），正在卸载旧版本并重新安装..."
+  adb uninstall com.shen.kouyu_english || true
   adb install -r "$APK_PATH"
+fi
 
-echo "▶️ 正在手机上启动 口语英语 App..."
+echo "▶️ 正在手机上启动 开口英语 App..."
 adb shell monkey -p com.shen.kouyu_english -c android.intent.category.LAUNCHER 1 > /dev/null 2>&1 || true
 
 echo "✅ 安装并启动成功！"

kouyu_english/lib/features/progress/progress_pages.dart

@@ -288,7 +288,7 @@ class _SettingsPageState extends State<SettingsPage> {
           style: TextStyle(fontSize: 12, color: AppColors.muted),
         ),
         DropdownButtonFormField<AiProviderType>(
-          initialValue: widget.state.aiProvider,
+          value: widget.state.aiProvider,
           decoration: const InputDecoration(
             labelText: '服务类型',
             border: OutlineInputBorder(),
@@ -313,6 +313,7 @@ class _SettingsPageState extends State<SettingsPage> {
           ],
           onChanged: (value) {
             if (value == null) return;
+            setState(() {
               widget.state.setAiProvider(value);
               if (value == AiProviderType.gemini &&
                   endpoint.text.trim().isEmpty) {
@@ -322,6 +323,7 @@ class _SettingsPageState extends State<SettingsPage> {
                     ? 'gemini-2.5-flash'
                     : model.text;
               }
+            });
           },
         ),
         TextField(