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

Package.swift

@@ -0,0 +1,26 @@
+// swift-tools-version: 6.0
+
+import PackageDescription
+
+let package = Package(
+    name: "ToLivePhoto",
+    platforms: [
+        .iOS(.v18)
+    ],
+    products: [
+        .library(
+            name: "LivePhotoCore",
+            targets: ["LivePhotoCore"]
+        )
+    ],
+    targets: [
+        .target(
+            name: "LivePhotoCore",
+            dependencies: []
+        ),
+        .testTarget(
+            name: "LivePhotoCoreTests",
+            dependencies: ["LivePhotoCore"]
+        )
+    ]
+)