feat(styles): learn the personal reply style incrementally

Regeneration merges the on-device learned evidence with dictation and reply
choices since the last generation instead of re-reading only the newest
~2,500 characters. It unlocks after 500 new characters, fades traits that
stop getting support, and fully relearns styles without saved evidence.

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **Managed ASR connect crash**: `URLSessionWebSocketTask.sendPing` can invoke its completion twice when the task is cancelled mid-ping, so opening a managed Volcengine session could trap on the second continuation resume (SIGTRAP). The handler now passes through a once-only gate. / **托管语音识别建连崩溃**：`URLSessionWebSocketTask.sendPing` 在 ping 在途时被取消会回调两次，打开托管火山引擎会话时第二次恢复 continuation 会触发 SIGTRAP 断言。回调现经一次性闸门过滤。
 - **Auto-reply storms from Universal Clipboard**: copying on a nearby Mac re-announces one copy under several pasteboard changeCounts, and each re-announcement re-armed auto reply/translate and the auto-reply guide — including on every later keyboard open, because re-ingesting the same text kept refreshing its 30-second hint window. A capture whose text is identical to the newest history entry is now treated as the same logical copy (bookkeeping only, no re-analysis), and auto actions additionally dedupe on a content fingerprint within a 30-second window. The same text fires once; copying something else and then re-copying the text still triggers. / **跨端剪贴板引发自动回复风暴**：在附近 Mac 上复制一次会被系统以多个 changeCount 重复宣告，且每次宣告都会重新武装自动回复/翻译与自动回复引导——由于同文本被重复入库并不断刷新 30 秒提示窗口，之后每次打开键盘也会再触发。现在，与最新历史条目文本相同的采集会被视为同一次复制（仅更新记账，不重新分析），自动动作再叠加内容指纹 + 30 秒窗口去重。同一文本只触发一次；复制其他内容后再重新复制该文本仍可触发。
 - **Style card captions**: resolve each built-in style’s short description through the in-app language override, so switching App Language updates the caption instead of showing a localization key or the system language. / **风格卡片说明**：内置风格的说明小字改为走应用内语言设置；切换 App 语言后说明会跟着变，而不再显示本地化 key 或跟随系统语言。
+- **Personal reply style keeps learning**: regenerating used only the newest ~2,500 characters, so new dictation pushed earlier learning out instead of adding to it. Regeneration is now incremental: it merges what the style already learned (kept on this device only) with dictation and reply choices since the last generation, unlocks after 500 new characters, and the card shows the cumulative character count plus progress since the last generation. Traits that stop getting new support fade out over a few rounds. A style without saved learning (older builds or another device) is relearned in full and replaced. / **个人回复风格持续学习**：此前重新生成只使用最新约 2,500 字，新听写会把早期学习挤掉而非叠加。现在改为增量重新生成：把该风格已学到的特征（仅保存在本机）与上次生成后的新听写和回复选择合并，新增满 500 字即可重新生成；卡片显示累计学习字数与自上次生成后的新增进度。长期没有新证据支持的特征会在几轮后自然淘汰。没有本机学习记录的风格（旧版本或其他设备生成）会全量重新学习并替换。
 
 ## [2.2.0] - 2026-09-18