feat: add optional loop field to DeviceInfo

Sources/DuooomiBleSDK/Models/DeviceInfo.swift

@@ -7,11 +7,13 @@ public struct DeviceInfo: Equatable {
     public let size: String
     public let brand: String
     public let powerlevel: Int
+    /// 播放模式（旧固件无此字段时为 nil）
+    public let loop: PlayMode?
 }
 
 extension DeviceInfo: Codable {
     enum CodingKeys: String, CodingKey {
-        case allspace, freespace, name, size, brand, powerlevel
+        case allspace, freespace, name, size, brand, powerlevel, loop
     }
 
     public init(from decoder: Decoder) throws {
@@ -35,6 +37,13 @@ extension DeviceInfo: Codable {
         // allspace/freespace: may come as number, string, or be missing
         allspace = Self.decodeFlexibleUInt64(container: container, key: .allspace)
         freespace = Self.decodeFlexibleUInt64(container: container, key: .freespace)
+
+        // loop: optional. Accept Int 0/1; anything else → nil.
+        if let raw = try? container.decode(Int.self, forKey: .loop), let mode = PlayMode(rawValue: raw) {
+            loop = mode
+        } else {
+            loop = nil
+        }
     }
 
     private static func decodeFlexibleUInt64(