feat: 初始化 Live Photo 项目结构

- 添加 PRD、技术规范、交互规范文档 (V0.2)
- 创建 Swift Package 和 Xcode 项目
- 实现 LivePhotoCore 基础模块
- 添加 HEIC MakerNote 元数据写入功能
- 创建项目结构文档和任务清单
- 添加 .gitignore 忽略规则

Sources/LivePhotoCore/MakerNotesPatcher.swift

@@ -0,0 +1,83 @@
+import Foundation
+
+/// 用于修复 HEIC 文件中的 Apple MakerNotes，添加 LivePhotoVideoIndex 字段
+/// CGImageDestination 无法正确写入 Int64 类型的 MakerNotes 字段，
+/// 所以我们使用预制的模板并在运行时替换关键字段
+public struct MakerNotesPatcher {
+
+    // MARK: - 模板中的偏移量（基于原生 iPhone 照片的 MakerNotes 分析）
+
+    /// ContentIdentifier 在 MakerNotes 模板中的偏移（36 字节 ASCII UUID + null）
+    private static let contentIdentifierOffset = 0x580  // 1408
+    private static let contentIdentifierLength = 36
+
+    /// LivePhotoVideoIndex 在 MakerNotes 模板中的偏移（8 字节 Big-Endian Int64）
+    private static let livePhotoVideoIndexOffset = 0x5a6  // 1446
+    private static let livePhotoVideoIndexLength = 8
+
+    /// 原生 iPhone MakerNotes 模板（从 iPhone 13 Pro Max 拍摄的 Live Photo 提取）
+    /// 包含完整的 Apple MakerNotes 结构，需要替换 ContentIdentifier 和 LivePhotoVideoIndex
+    private static let makerNotesTemplate: Data = {
+        // Base64 编码的 MakerNotes 模板
+        let base64 = """
+        QXBwbGUgaU9TAAABTU0APQABAAkAAAABAAAAEAACAAcAAAIAAAAC8AADAAcAAABoAAAE8AAEAAkA\
+        AAABAAAAAQAFAAkAAAABAAAAqQAGAAkAAAABAAAApQAHAAkAAAABAAAAAQAIAAoAAAADAAAFWAAM\
+        AAoAAAACAAAFcAANAAkAAAABAAAAFwAOAAkAAAABAAAABAAQAAkAAAABAAAAAQARAAIAAAAlAAAF\
+        gAAUAAkAAAABAAAACgAXABAAAAABAAAFpgAZAAkAAAABAAAAAgAaAAIAAAAGAAAFrgAfAAkAAAAB\
+        AAAAAAAgAAIAAAAlAAAFtAAhAAoAAAABAAAF2gAjAAkAAAACAAAF4gAlABAAAAABAAAF6gAmAAkA\
+        AAABAAAAAwAnAAoAAAABAAAF8gAoAAkAAAABAAAAAQArAAIAAAAlAAAF+gAtAAkAAAABAAATXAAu\
+        AAkAAAABAAAAAQAvAAkAAAABAAAAMAAwAAoAAAABAAAGIAAzAAkAAAABAAAQAAA0AAkAAAABAAAA\
+        BAA1AAkAAAABAAAAAwA2AAkAAAABAADnJAA3AAkAAAABAAAABAA4AAkAAAABAAACPgA5AAkAAAAB\
+        AAAAAAA6AAkAAAABAAAAAAA7AAkAAAABAAAAAAA8AAkAAAABAAAABAA9AAkAAAABAAAAAAA/AAkA\
+        AAABAAAAOwBAAAcAAABQAAAGKABBAAkAAAABAAAAAABCAAkAAAABAAAAAABDAAkAAAABAAAAAABE\
+        AAkAAAABAAAAAABFAAkAAAABAAAAAABGAAkAAAABAAAAAABIAAkAAAABAAACPgBJAAkAAAABAAAA\
+        AABKAAkAAAABAAAAAgBNAAoAAAABAAAGeABOAAcAAAB5AAAGgABPAAcAAAArAAAG+gBSAAkAAAAB\
+        AAAAAQBTAAkAAAABAAAAAQBVAAkAAAABAAAAAQBYAAkAAAABAAAHAwBgAAkAAAABAAASAABhAAkA\
+        AAABAAAAGgAAAAC9AtMCxAKWAlsCIALqAbwBkgFrAUYBJQEIAfEA3QDMAAMDMwNAA/QCmQJWAg0C\
+        1QGoAX4BUwEtAQ8B9QDhAM0ALANqA2oDTAPrAnUCKALpAb4BhgFWATABEAH0AN4AyQA9A7oDwgNP\
+        A7gCXAIYAugBqwF2AUwBJgEGAeoA0gC+ANECrwPSAxIDZAIVAt4BqwF8AVABKQEHAekA0AC6AKgA\
+        zwFCAnYCBAK/AZYBcwFQAS8BDQHvANQAvQCpAJgAigDUAP8AGgEVARoB5QC6AMUAsACsAJkAggBy\
+        AGQAXABTAGAAaABqAGYAXABMAEcARwBCAEEAPgAvACQAJAAlACoARgBIAEcARAA/ADcAMwAvACoA\
+        KAAnACEAHQAfAB8AIAAxADIAMQAwAC4AKwAnACcAJQAfABwAGgAXABkAEwAUACkAKgAmACQAIgAg\
+        ACEAIgAgAB4AHAAZABgAFAAXABUAIgAcABoAGwAaABcAHAAdABkAGAAYABgAFwAaABgAGAAaABsA\
+        GgAYABUAEwAWABcAEwAWABcAFQAVABYAEwAUABoAFwAWABMAEgATABAADwATABMAEgANAA8ADwAP\
+        AAwAEwAVABIAEwANABUAEwATABIADAAPAAsAEAASAA8ADgARABEADwAMAAwADwAWABMAEgASABQA\
+        DQAPAAoADAAOAGJwbGlzdDAw1AECAwQFBgcIVWZsYWdzVXZhbHVlWXRpbWVzY2FsZVVlcG9jaBAB\
+        EwABVEUBR7fxEjuaygAQAAgRFx0nLS84PQAAAAAAAAEBAAAAAAAAAAkAAAAAAAAAAAAAAAAAAAA/\
+        ///J3gAANk3//8R4AAe+////5bUAAVy+AAAAOwAAAQAAAAAnAAABAAAAAAAAAAAAAAAAAAAAALtA\
+        AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABI\
+        RUlDAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\
+        AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\
+        AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAbwBwAGwAaQBzAHQAMAAwANQBAgMEBQYHCFEzUTFR\
+        MlEwEAQiAAAAACQ/AAAAEAEIERMVFxkbICUAAAAAAAABAQAAAAAAAAAJAAAAAAAAAAAAAAAAAAAA\
+        JwAC8/UAABV+YnBsaXN0MDDSAQIDSFExUTIQA6IFCtIGBwgJUzIuMVMyLjIjQEsf2IAAAACJQAAA\
+        AAAAAADSBgcLDCM/4hqAAAAAAKNAVMAAAAAAAAgNDxETFhsfIywlOkMAAAAAAAABAQAAAAAAAAAL\
+        AAAAAAAAAAAAAAAAAAAAQQAAAAA=
+        """
+        return Data(base64Encoded: base64.replacingOccurrences(of: "\\\n", with: "").replacingOccurrences(of: "\n", with: ""))!
+    }()
+
+    /// 创建自定义的 MakerNotes 数据
+    /// - Parameters:
+    ///   - contentIdentifier: Live Photo 的 Content Identifier (UUID 字符串格式)
+    ///   - livePhotoVideoIndex: Live Photo Video Index (通常是帧索引的 Float32 bitPattern)
+    /// - Returns: 修改后的 MakerNotes 数据
+    public static func createMakerNotes(
+        contentIdentifier: String,
+        livePhotoVideoIndex: Int64
+    ) -> Data {
+        var data = makerNotesTemplate
+
+        // 替换 ContentIdentifier
+        let uuidData = contentIdentifier.data(using: .ascii)!
+        let paddedUUID = uuidData + Data(repeating: 0, count: max(0, contentIdentifierLength - uuidData.count))
+        data.replaceSubrange(contentIdentifierOffset..<(contentIdentifierOffset + contentIdentifierLength), with: paddedUUID.prefix(contentIdentifierLength))
+
+        // 替换 LivePhotoVideoIndex (Big-Endian)
+        var bigEndianValue = UInt64(bitPattern: livePhotoVideoIndex).bigEndian
+        let indexData = Data(bytes: &bigEndianValue, count: livePhotoVideoIndexLength)
+        data.replaceSubrange(livePhotoVideoIndexOffset..<(livePhotoVideoIndexOffset + livePhotoVideoIndexLength), with: indexData)
+
+        return data
+    }
+}