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/Protocol/ProtocolManager.swift

@@ -0,0 +1,165 @@
+import Foundation
+
+public enum ProtocolManager {
+
+    // MARK: - Checksum
+
+    /// 计算校验和：所有字节求和后取二进制补码的低 8 位
+    /// checksum = (~sum + 1) & 0xFF
+    public static func calculateChecksum(_ data: Data) -> UInt8 {
+        var sum: UInt32 = 0
+        for byte in data {
+            sum += UInt32(byte)
+        }
+        return UInt8((~sum &+ 1) & 0xFF)
+    }
+
+    /// 校验给定数据的校验和是否匹配。
+    /// - Parameters:
+    ///   - data: 用于计算校验的字节序列（不含最后的校验位）。
+    ///   - expected: 期望的校验和。
+    /// - Returns: 是否匹配。
+    public static func verifyChecksum(_ data: Data, expected: UInt8) -> Bool {
+        calculateChecksum(data) == expected
+    }
+
+    // MARK: - Frame Creation
+
+    /// 根据数据大小自动选择单帧或分片
+    /// - Throws: 当 payload 超过 UInt16 分页能力时（> 65535 个分片）抛出 invalidFrame
+    public static func createFrames(
+        type: UInt8,
+        data: Data,
+        head: FrameHead = .appToDevice,
+        maxDataSize: Int = FrameConstants.maxDataSize
+    ) -> [Data] {
+        // subpageTotal/curPage are encoded as UInt16, so the absolute ceiling is 65535 pages.
+        // Returning [] keeps the call non-throwing for backwards compatibility; callers (the
+        // protocol service / file transfer) detect the empty array as a payload-too-large signal.
+        let maxChunk = max(1, maxDataSize)
+        let totalPages = (data.count + maxChunk - 1) / maxChunk
+        if totalPages > Int(UInt16.max) {
+            return []
+        }
+
+        if data.count <= maxDataSize {
+            return [createSingleFrame(type: type, data: data, head: head)]
+        } else {
+            return createFragmentedFrames(type: type, data: data, head: head, maxDataSize: maxChunk)
+        }
+    }
+
+    private static func createSingleFrame(type: UInt8, data: Data, head: FrameHead) -> Data {
+        let totalSize = FrameConstants.headerSize + data.count + FrameConstants.footerSize
+        var buffer = Data(capacity: totalSize)
+
+        // Header: head(1) + type(1) + subpageTotal(2) + curPage(2) + dataLen(2)
+        buffer.append(head.rawValue)
+        buffer.append(type)
+        buffer.append(0) // subpageTotal high
+        buffer.append(0) // subpageTotal low
+        buffer.append(0) // curPage high
+        buffer.append(0) // curPage low
+        buffer.append(UInt8((data.count >> 8) & 0xFF)) // dataLen high
+        buffer.append(UInt8(data.count & 0xFF))         // dataLen low
+
+        // Data
+        buffer.append(data)
+
+        // Checksum (calculated on everything before checksum)
+        let checksum = calculateChecksum(buffer)
+        buffer.append(checksum)
+
+        return buffer
+    }
+
+    private static func createFragmentedFrames(
+        type: UInt8,
+        data: Data,
+        head: FrameHead,
+        maxDataSize: Int
+    ) -> [Data] {
+        let totalPages = (data.count + maxDataSize - 1) / maxDataSize
+        var frames: [Data] = []
+        frames.reserveCapacity(totalPages)
+
+        for i in 0..<totalPages {
+            let start = i * maxDataSize
+            let end = min(start + maxDataSize, data.count)
+            let chunk = data[start..<end]
+
+            var buffer = Data(capacity: FrameConstants.headerSize + chunk.count + FrameConstants.footerSize)
+
+            buffer.append(head.rawValue)
+            buffer.append(type)
+
+            // subpageTotal (big-endian UInt16)
+            buffer.append(UInt8((totalPages >> 8) & 0xFF))
+            buffer.append(UInt8(totalPages & 0xFF))
+
+            // curPage: 页号从 (total-1) 倒数到 0
+            let curPageVal = totalPages - 1 - i
+            buffer.append(UInt8((curPageVal >> 8) & 0xFF))
+            buffer.append(UInt8(curPageVal & 0xFF))
+
+            // dataLen
+            buffer.append(UInt8((chunk.count >> 8) & 0xFF))
+            buffer.append(UInt8(chunk.count & 0xFF))
+
+            // data
+            buffer.append(contentsOf: chunk)
+
+            // checksum
+            let checksum = calculateChecksum(buffer)
+            buffer.append(checksum)
+
+            frames.append(buffer)
+        }
+
+        return frames
+    }
+
+    // MARK: - Frame Parsing
+
+    /// 解析原始二进制为协议帧。
+    /// - Parameter data: 含有完整帧内容的字节序列。
+    /// - Returns: 若校验与长度正确，返回 `ProtocolFrame`，否则返回 `nil`。
+    public static func parseFrame(_ data: Data) -> ProtocolFrame? {
+        let minSize = FrameConstants.headerSize + FrameConstants.footerSize
+        guard data.count >= minSize else { return nil }
+
+        let head = data[data.startIndex]
+        guard head == FrameHead.deviceToApp.rawValue || head == FrameHead.appToDevice.rawValue else {
+            return nil
+        }
+
+        let type = data[data.startIndex + 1]
+        let subpageTotal = UInt16(data[data.startIndex + 2]) << 8 | UInt16(data[data.startIndex + 3])
+        let curPage = UInt16(data[data.startIndex + 4]) << 8 | UInt16(data[data.startIndex + 5])
+        let dataLen = UInt16(data[data.startIndex + 6]) << 8 | UInt16(data[data.startIndex + 7])
+
+        let expectedSize = FrameConstants.headerSize + Int(dataLen) + FrameConstants.footerSize
+        guard data.count >= expectedSize else { return nil }
+
+        let dataStart = data.startIndex + FrameConstants.headerSize
+        let dataEnd = dataStart + Int(dataLen)
+        let frameData = data[dataStart..<dataEnd]
+        let checksum = data[dataEnd]
+
+        // Verify checksum on everything before checksum byte
+        let dataToCheck = data[data.startIndex..<dataEnd]
+        guard verifyChecksum(dataToCheck, expected: checksum) else {
+            return nil
+        }
+
+        return ProtocolFrame(
+            head: head,
+            type: type,
+            subpageTotal: subpageTotal,
+            curPage: curPage,
+            dataLen: dataLen,
+            data: Data(frameData),
+            checksum: checksum
+        )
+    }
+}