demo app + SDK updates:\n- Add direct ANI transfer (prepare -> transfer)\n- Add firmware update flow (fetch latest w/ x-api-key, OTA transfer)\n- Extract x-api-key to NetworkConstants\n- Rename example app to demo; move folder and entry to DemoApp\n- Switch from SPM package dependency to local framework target\n- Enable automatic Info.plist generation for framework target\n- Add placeholder test to satisfy SwiftPM test target\n- Regenerate XcodeGen project (demo.xcodeproj)

Sources/DuooomiBleSDK/Services/FileTransferService.swift

@@ -0,0 +1,48 @@
+import Foundation
+
+/// 文件传输服务：下载文件并通过协议发送二进制数据
+final class FileTransferService {
+    private let protocolService: BleProtocolService
+
+    init(protocolService: BleProtocolService) {
+        self.protocolService = protocolService
+    }
+
+    /// 传输文件到设备
+    /// - Parameters:
+    ///   - fileUri: 本地 file:// URL 或远程 https:// URL
+    ///   - commandType: 传输命令类型
+    ///   - onProgress: 进度回调 0.0 ~ 1.0
+    func transferFile(
+        fileUri: String,
+        commandType: CommandType,
+        onProgress: ((Double) -> Void)? = nil
+    ) async throws {
+        BleLog.i("Load file: \(fileUri)", "Transfer")
+        let data = try await loadFileData(from: fileUri)
+        BleLog.d("File loaded: size=\(data.count) bytes", "Transfer")
+
+        try await protocolService.send(
+            type: commandType.rawValue,
+            data: data,
+            onProgress: onProgress
+        )
+    }
+
+    private func loadFileData(from uri: String) async throws -> Data {
+        guard let url = URL(string: uri) else {
+            throw DuooomiBleError.transferFailed("Invalid URL: \(uri)")
+        }
+
+        if url.isFileURL {
+            return try Data(contentsOf: url)
+        } else {
+            let (data, response) = try await URLSession.shared.data(from: url)
+            guard let httpResponse = response as? HTTPURLResponse,
+                  (200...299).contains(httpResponse.statusCode) else {
+                throw DuooomiBleError.transferFailed("Failed to download file: \(uri)")
+            }
+            return data
+        }
+    }
+}