v0.15: Live Photo 生产规则 — 平台限制、拼图版式、长视频处理、发布提醒、可见文案规则

新增 Live Photo 正式能力：单视频、二宫格、三宫格、四宫格、三连拼图、
长视频低成本诊断。增加 references/live-photo-production.md 生产规范、
scripts/ 工具链（contact sheet / .pvt 打包 / Apple metadata）、
validator R8 visual bounds + R9 title gap、文档约束测试。

由 Codex 完成主体实现。

scripts/add-livephoto-maker-note.swift

@@ -0,0 +1,44 @@
+import Foundation
+import ImageIO
+
+guard CommandLine.arguments.count == 4 else {
+    fputs("Usage: swift add-livephoto-maker-note.swift <input.jpg> <output.jpg> <asset-id>\n", stderr)
+    exit(2)
+}
+
+let inputURL = URL(fileURLWithPath: CommandLine.arguments[1])
+let outputURL = URL(fileURLWithPath: CommandLine.arguments[2])
+let assetIdentifier = CommandLine.arguments[3]
+
+guard let source = CGImageSourceCreateWithURL(inputURL as CFURL, nil) else {
+    fputs("Could not open input image\n", stderr)
+    exit(1)
+}
+
+guard let imageType = CGImageSourceGetType(source) else {
+    fputs("Could not determine image type\n", stderr)
+    exit(1)
+}
+
+let imageCount = CGImageSourceGetCount(source)
+
+guard let destination = CGImageDestinationCreateWithURL(outputURL as CFURL, imageType, imageCount, nil) else {
+    fputs("Could not create output image\n", stderr)
+    exit(1)
+}
+
+for index in 0..<imageCount {
+    var properties = (CGImageSourceCopyPropertiesAtIndex(source, index, nil) as? [String: Any]) ?? [:]
+    var makerApple = (properties[kCGImagePropertyMakerAppleDictionary as String] as? [String: Any]) ?? [:]
+    makerApple["17"] = assetIdentifier
+    properties[kCGImagePropertyMakerAppleDictionary as String] = makerApple
+
+    CGImageDestinationAddImageFromSource(destination, source, index, properties as CFDictionary)
+}
+
+guard CGImageDestinationFinalize(destination) else {
+    fputs("Could not finalize output image\n", stderr)
+    exit(1)
+}
+
+print("Wrote Apple MakerNote asset identifier: \(assetIdentifier)")