feat: Flutter 客户端 App + Web UI APK 下载入口

- 新增 Flutter 跨平台客户端项目 (clients/flutter/)
  - 29 个 Dart 文件: 服务层/状态管理/5个页面/BLE配网
  - BLE 蓝牙配网: 扫描设备、写入WiFi凭据、配网状态监听
  - HTTP API 客户端: 覆盖全部端点 (播放/场景/WiFi/视频/配置/文件/插件)
  - WebSocket 实时通信: 事件流 + 自动重连
  - 暗色主题 Material 3 UI, 中文界面
  - Android 配置: minSdkVersion 21, BLE/网络权限
  - PRD 产品需求文档 + 开发任务看板
- Web UI 添加 APK 下载入口 (routes.rs)
  - 下载弹窗 + 二维码 + /download/{filename} 静态文件路由
- BLE 插件增加自动重连循环 (ble/mod.rs)
- BLE 默认设备名修正为 'Showen' (config.rs)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/plugins/ble/gatt.rs

@@ -165,8 +165,8 @@ struct AdvertisementData {
 pub fn run_ble_service(
     device_name: String,
     tx: mpsc::Sender<Envelope>,
-    control_rx: Receiver<BleControl>,
-    stop: Arc<AtomicBool>,
+    control_rx: &Receiver<BleControl>,
+    stop: &Arc<AtomicBool>,
 ) -> Result<()> {
     let shared = SharedState::new(tx.clone());
 
@@ -277,6 +277,9 @@ pub fn run_ble_service(
     let adapter_path = find_adapter(&conn)?;
     configure_adapter(&conn, &adapter_path, &device_name)?;
 
+    // 先尝试清理上一次进程残留的注册（防止崩溃后 BlueZ 状态残留）
+    let _ = unregister_ble_objects(&conn, &adapter_path);
+
     // 非阻塞发送 RegisterApplication + RegisterAdvertisement
     let _gatt_serial = send_register_gatt_app(&conn, &adapter_path)?;
     let _ad_serial = send_register_advertisement(&conn, &adapter_path)?;
@@ -554,6 +557,20 @@ fn configure_adapter(conn: &Connection, adapter_path: &str, device_name: &str) -
     adapter
         .set(ADAPTER_IFACE, "Alias", device_name.to_string())
         .context("failed to set BLE adapter alias")?;
+    adapter
+        .set(ADAPTER_IFACE, "Discoverable", true)
+        .context("failed to set BLE adapter discoverable")?;
+    // DiscoverableTimeout=0 表示永久可发现
+    adapter
+        .set(ADAPTER_IFACE, "DiscoverableTimeout", 0u32)
+        .context("failed to set DiscoverableTimeout")?;
+    adapter
+        .set(ADAPTER_IFACE, "Pairable", true)
+        .context("failed to set BLE adapter pairable")?;
+    // PairableTimeout=0 表示永久可配对
+    adapter
+        .set(ADAPTER_IFACE, "PairableTimeout", 0u32)
+        .context("failed to set PairableTimeout")?;
     Ok(())
 }
 

src/plugins/ble/mod.rs

@@ -82,11 +82,32 @@ impl Plugin for BlePlugin {
         self.control_tx = Some(control_tx);
 
         self.worker = Some(thread::spawn(move || {
-            let result = gatt::run_ble_service(device_name, tx, control_rx, stop);
-            if let Err(ref error) = result {
-                eprintln!("[BlePlugin] worker exited with error: {error:#}");
+            // 自动重连循环：BLE 服务出错后等待 3 秒重试
+            loop {
+                if stop.load(Ordering::SeqCst) {
+                    return Ok(());
+                }
+                let result =
+                    gatt::run_ble_service(device_name.clone(), tx.clone(), &control_rx, &stop);
+                match result {
+                    Ok(()) => return Ok(()),
+                    Err(ref error) => {
+                        if stop.load(Ordering::SeqCst) {
+                            return Ok(());
+                        }
+                        eprintln!(
+                            "[BlePlugin] worker error: {error:#}, restarting in 3 seconds..."
+                        );
+                        // 等待 3 秒，但如果 stop 被设置则立即退出
+                        for _ in 0..30 {
+                            if stop.load(Ordering::SeqCst) {
+                                return Ok(());
+                            }
+                            thread::sleep(std::time::Duration::from_millis(100));
+                        }
+                    }
+                }
             }
-            result
         }));
         Ok(())
     }