iOS 原生客户端：libwebrtc 数据面 + UX 改造 + 品牌/字体 + 全平台平均速度

- 原生数据面 libwebrtc（PLAN 决策 F）：新增 Engine/LibWebRtcEngine.swift（RTCPeerConnection，端口 engine.go/session.go 线协议 + 水位背压 + ack 完成 + 不冲突落盘）；NativeTransfer.swift 的 P2PEventsBridge 改 conform P2PEngineDelegate（去 gomobile）；EngineController 4 个 p2p RPC 改调新引擎（completion-based + resolveOnMain）。stasel/WebRTC M149 经 SPM（exactVersion 149.0.0）。环回端到端 20MB 逐字节测过（Tests/）
- UX 改造（PARITY 残余项 1/2）：新增 SendComposeSheet（发送预览＝文件名 + 选设备，手动多选与分享共用）；分享直入预览 + scenePhase .active 兜底（修“分享后必须重启 app”）；重写 MessagesView（按设备会话 + 每设备未读红点 + 删单条 / 删整设备历史）；EngineController 加 conversations / unread 模型
- 品牌 logo：新增 Shared/Brand.swift（BrandMark / Wordmark / BrandLockup / BrandHero）+ Brand.xcassets/LogoMark；登录页 / 传输空态 / 设置头 / 控制中心控件接 logo；Theme 加 cdropAmber
- 字体（对齐 web，仅主 app）：新增 BrandFonts.swift（Orbit Gothic + Maple Mono woff2 运行期 CTFontManager 注册 + UIKit 外观代理 + .oXxx / .maple 助手）；Fredoka SemiBold 字标；7 视图 .font sweep。字体不入库——.gitignore 排除 + just ios-fonts 构建前从 CDN / Google Fonts 拉取，见 Sources/Fonts/README.md
- 分享引导：新增 Share/ShareGuideView（吉祥物卡 + “打开 Commilitia Drop”）；ShareViewController 健壮 staging（文件 / 数据双路）+ 响应链 IMP 唤起宿主
- 全平台平均速度：传输完成态显平均速度（总字节 / 总耗时）而非末次瞬时——web store/slices/transfer.ts + TransferRow.tsx + iOS RootView 卡片 / 详情；i18n 加 transfer.avgRate
- 工程：project.yml 接 SPM WebRTC + CDropTests + Fredoka UIAppFonts + Share i18n；Justfile 加 ios-sim-build + ios-fonts / ios-fonts-fredoka 配方
- 文档：ios/PLAN.md（决策 F + §10 UX + §11 品牌/字体 + §12 平均速度）、ios/PARITY.md（字体分叉条目更新 + 2026-06-28 漂移行）

ios/CDrop/Sources/Resources/i18n/en-US.json

@@ -271,6 +271,7 @@
   "transfer.stalled": "Looks stalled ({{seconds}}s without progress)",
   "transfer.bytesProgress": "{{sent}} / {{total}}",
   "transfer.bytesRate": "{{rate}}/s",
+  "transfer.avgRate": "Avg {{rate}}/s",
   "transfer.debug.toggle": "Debug",
   "transfer.debug.iceGathering": "Gathering",
   "transfer.debug.iceConnection": "Connection",
@@ -354,13 +355,20 @@
   "ios.tab.messages": "Messages",
   "ios.send.fromFiles": "From Files",
   "ios.send.fromPhotos": "From Photos",
+  "ios.send.previewTitle": "Send Files",
+  "ios.send.files": "Files",
+  "ios.send.send": "Send",
   "ios.messages.empty": "No messages yet",
   "ios.messages.noPeers": "No device to message",
   "ios.messages.placeholder": "Type a message…",
+  "ios.messages.viewOnly": "Offline — viewing only",
+  "ios.messages.deleteConversation": "Delete Conversation",
+  "ios.messages.startHint": "Tap to start a conversation",
+  "ios.messages.youPrefix": "You: ",
   "ios.records.clear": "Clear",
   "ios.records.clearConfirm": "Clear all records? This cannot be undone.",
   "ios.transfer.cancel": "Cancel transfer",
-  "ios.transfer.forceRelay": "Relay now",
+  "ios.transfer.forceRelay": "Relay",
   "ios.settings.deviceCount": "Known Devices",
   "ios.settings.signaling": "Signaling",
   "ios.settings.presenceEvents": "Presence Events",
@@ -375,6 +383,11 @@
   "ios.bg.title": "Transferring files",
   "ios.bg.subtitle": "Continues in the background",
   "ios.share.title": "Send {{n}} file(s) to a device",
+  "ios.share.guide.preparing": "Preparing…",
+  "ios.share.guide.ready": "{{n}} file(s) ready",
+  "ios.share.guide.empty": "Couldn't add files",
+  "ios.share.guide.hint": "Open Commilitia Drop to pick a device",
+  "ios.share.guide.open": "Open Commilitia Drop",
   "ios.control.upload": "Upload Clipboard",
   "ios.control.pull": "Pull Clipboard",
   "ios.control.sessionLabel": "{{name}} · Control",
@@ -383,6 +396,8 @@
   "ios.logs.empty": "No logs yet",
   "ios.logs.clear": "Clear Logs",
   "ios.logs.copy": "Copy All",
+  "ios.logs.session": "Session",
+  "ios.logs.ungrouped": "Other",
   "ios.scan.entry": "Scan to Sign In",
   "ios.scan.title": "Scan QR Code",
   "ios.scan.hint": "Point at the sign-in QR code on another device",