fix(clipboard): enforce plain-text output shape for Speak as Me

The speak-as-me skill inherited the Reply contract's JSON variants and
occasionally echoed the personal-style XML tags into the output. The
prompt now demands one ready-to-send plain-text paragraph, forbids JSON,
code fences, Markdown, lists, preambles, and multiple variants, and marks
the style block as prompt-internal packaging. Length follows the user's
natural voice instead of the mechanical ±20% cap.

CHANGELOG.md

@@ -8,9 +8,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Changed
+- **Product page redesign**: rebuild the GitHub Pages home as a dark product stage with the new Icon Composer app icon, the three-device hero visual, and real on-device videos and UI cards replacing hand-drawn mockups; add 2.1 selling points (personal style, three-tone replies, monthly usage calendar, EventKit skills export, guided trials and credit rewards), a TestFlight link, and self-hosted inline SVG icons; bump page references to 2.1.0. / **产品页重设计**：GitHub Pages 主页改为深色产品舞台，启用 Icon Composer 新图标与三端同框主视觉，以实机视频与真实界面卡片取代手绘示意；补齐 2.1 卖点（专属风格、三语气个性回复、月度用量日历、EventKit 技能写入、引导体验与积分奖励），新增 TestFlight 入口，图标改为自托管内联 SVG；页面版本号更新至 2.1.0。
 - **Host-only analytics recording**: the keyboard extension no longer opens the analytics or keyboard-usage SQLite queues. The host app is the only process that records and uploads events, so hiding the keyboard cannot hold WAL locks and get killed as `0xdead10cc`. Keyboard-activated and per-keystroke usage events are no longer collected. / **仅主 App 记埋点**：键盘扩展不再打开统计与键盘用量 SQLite 队列；开库、记账与上传只在主 App 进行，收起键盘时不会因 WAL 锁被系统以 `0xdead10cc` 终止。不再采集「键盘激活」和逐次按键用量。
 
 ### Fixed
+- **Speak as Me output shape**: the skill could answer with raw JSON variants or echo the personal-style XML tags into the result. The prompt now requires one ready-to-send plain-text rewrite, and length follows your natural voice instead of a mechanical ±20% cap. / **「像我所说」输出形态**：该技能可能返回原始 JSON 候选，或把个人风格的 XML 标记带进结果。现在提示词要求只输出一段可直接发送的文本，长度改为跟随你的自然表达节奏，不再机械限制 ±20%。
 - **Clipboard history reverting deletes**: history is one shared blob, and the main App kept an in-memory copy that only refreshed when a screen appeared — so a delete made there could write back entries the keyboard had just captured or removed, and a clear done in the keyboard could be undone entirely. Both processes now announce their writes to each other, and the main App re-reads history whenever it returns to the foreground. / **剪贴板历史撤销删除**：历史记录是整块共享数据，而主 App 仅在页面出现时刷新内存副本——因此在主 App 中删除一条，可能把键盘刚采集或刚删除的条目重新写回，在键盘里执行的清空也可能被整体撤销。现在两端写入时会互相通知，主 App 每次回到前台也会重新读取历史。
 - **Keyboard crash loop on memory relief**: recording a memory milestone could request relief while relief was already running, and the two sides called each other until the keyboard extension exhausted its stack (SIGSEGV grouped under `KeyboardViewController.viewDidLoad`). Reentrancy guards on both the controller and the telemetry side break the cycle. / **键盘内存降级递归崩溃**：记录内存里程碑时可能再次请求降级，两侧互相回调直至扩展栈溢出（崩溃聚合在 `KeyboardViewController.viewDidLoad`）。控制器与遥测两侧均加重入保护，打断循环。
 - **Keyboard killed while reading credentials**: the extension resolved API keys synchronously on the main thread at every config read — including boot and Flow session setup — and a Keychain read in flight while the system suspends the keyboard is killed as `0xdead10cc`. Legacy credential migration is now attempted once per install instead of on every load, credential availability refreshes asynchronously after appear, and the onboarding gate reads the Keychain off the main thread. / **键盘读取凭据时被系统终止**：扩展此前每次读取配置都会在主线程同步解析 API 密钥（含启动与 Flow 会话建立），而挂起窗口内进行中的钥匙串读取会被系统以 `0xdead10cc` 查杀。旧凭据迁移改为每次安装仅尝试一次，凭据可用性改为键盘出现后异步刷新，入门引导门控的钥匙串读取移出主线程。