merge: bring pinyin habit ranking into English keyboard branch

Keep English QuickType/mmap and Chinese schema hygiene on one branch.
Secure fields skip Rime; English still loads its lexicon only while English is active.

CHANGELOG.md

@@ -12,6 +12,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **System English lexicon**: typing uses `UITextChecker` completions/guesses and `requestSupplementaryLexicon` contact names / text replacements. / **系统英文词库**：打字使用 `UITextChecker` 补全/猜测，以及 `requestSupplementaryLexicon` 的通讯录名与文本替换。
 - **QWERTY proximity correction**: fat-finger substitutions on neighboring keys (for example `gppd` → `good`) outrank distant edit-distance neighbors. / **邻键纠错**：相邻键的胖手指替换（如 `gppd` → `good`）优先于远键编辑距离。
 - **Larger English word list**: about 40k unigrams and truncated bigrams, derived from Peter Norvig’s public-domain n-gram counts, shipped as an mmap binary so the keyboard extension does not parse them into Swift dictionaries. / **更大英文词表**：约 4 万 unigram 与截断 bigram，来自 Peter Norvig 公有领域 n-gram 计数，以 mmap 二进制随扩展加载，避免解析进 Swift 字典。
+- **Pinyin abbreviation ranking**: drop dialect single-letter syllables (`m` / `n` / `ng` / `hm`) before abbrev so mixes like `wom` prefer 我们, matching rime-pinyin-simp; full pinyin also allows `zh` / `ch` / `sh` two-key abbrev (resource version `2.4.0`). / **拼音简拼排序**：在简拼前擦掉方言单字母音节（`m` / `n` / `ng` / `hm`），使 `wom` 一类混拼优先「我们」，对齐 rime-pinyin-simp；全拼同时支持 `zh` / `ch` / `sh` 两键简拼（资源版本 `2.4.0`）。
+- **Clear typing habits**: Settings → Text Input can reset learned Chinese Rime user dictionaries and English boosts without deleting the personal dictionary. / **清除打字习惯**：设置 → 文本输入可重置中文 Rime 用户词库与英文加分，不删除个性词库。
 - **Overlapping key presses**: the typing grid tracks multiple fingers, so the next key can go down before the previous lifts. Pending letters commit in press order (not release order); Shift can be held with one finger while another types. / **叠指连打**：打字网格跟踪多指，上一键未松开也可按下下一键。未提交的字母按按下顺序出字（而非抬手顺序）；一只手指按住 Shift 时另一只可打字。
 - **Period shortcut**: in English, a second Space shortly after a Space that follows a word becomes `. ` and arms sentence Shift, matching the system "." Shortcut. / **句号快捷**：英文下，在单词后的空格上短时间内再按一次空格会变成 `. ` 并点亮句首 Shift，对齐系统「句号快捷」。
 - **Return key labels**: Go / Search / Send / Done / Next / Join and the other `UIReturnKeyType` values show their system captions on the green action key instead of collapsing to Send or a return arrow. / **回车键文案**：前往 / 搜索 / 发送 / 完成 / 下一项 / 加入等 `UIReturnKeyType` 在绿色动作键上显示系统对应文案，不再一律变成「发送」或换行箭头。
@@ -27,6 +29,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **Keyboard input tabs**: the four-tab capsule is centered independently of the side controls, with equal 42 pt hit widths and a translucent-black light-mode track. AI and Voice use enlarged `sparkle` and `waveform.mid` symbols, and the leading logo is 16 pt tall. / **键盘输入标签**：四标签胶囊不受两侧控件影响并在键盘上独立居中，点击宽度统一为 42 pt，浅色模式轨道使用半透明黑色；AI 与语音使用放大的 `sparkle` 和 `waveform.mid` 图标，左侧 Logo 高度为 16 pt。
 - **English lexicon mmap**: the 40k-word English table loads only in English and stays file-mapped; Chinese typing no longer pulls it in on keyboard appear. / **英文词表 mmap**：4 万词英文表仅在英文加载且走文件映射；中文打字不再在唤起键盘时一并灌入。
 - **English autocorrect conservatism**: Title Case / short / ALL CAPS tokens are not replaced, except same-length transpositions (`Teh` → `The`). Machine-applied corrections no longer boost the replacement; rejecting them learns the original. / **英文自动更正更克制**：Title Case / 短词 / 全大写默认不改，仅保留同长换位（`Teh` → `The`）。机器改写不再给新词加分；拒绝纠错会学会原文。
+- **Chinese user-dict flush**: leaving the typing surface finalizes librime so user-frequency ticks persist; secure fields insert Latin and skip Rime so passwords are not learned. / **中文用户词落盘**：离开打字表面时 finalize librime，使用频度得以保存；安全输入框改为直接插入拉丁字母、不进 Rime，避免把密码写入用户词库。
 
 ### Fixed
 - **Keyboard switch crash**: `requestSupplementaryLexicon` completion hops to the main actor before writing session state, so switching to OSG Keyboard no longer traps on `com.apple.TextInput.lexicon-request`. / **切换键盘崩溃**：`requestSupplementaryLexicon` 回调先回到主线程再写会话状态，切换到 OSG Keyboard 不再在 `com.apple.TextInput.lexicon-request` 上触发隔离断言。