feat: 字体与高亮系统改进（CJK 对齐、ReDoS 防护、链接规则、崩溃类设置修复）

基于两轮专项调研（字体/高亮各两路，子代理实测探针交叉印证）实施的完整改进。

## 修复的真实 bug

**设置越界导致窗格永久死亡（用户报告）**
行高设 0.95 → xterm 构造/热更抛错 → 错误边界卸载整个 dockview 窗格；坏值已
落盘，每次重启都崩。根因是一整类缺陷：UI 允许值 / 配置能写值 与 xterm 硬约束
不一致，且主进程不校验。同类还有 scrollback<0（抛错）、cursorStyle 非法值
（更隐蔽：构造期被吞掉、只有热更期抛错，导致「重试」按钮永远无效、窗格死循环）。

修复：FONT_LIMITS/CURSOR_STYLES/RENDERER_MODES 收拢到 shared 层单一来源，
主进程加载时钳制 + 白名单化，healClampedFontSettings() 回写自愈；设置页
InputNumber、字体热键共用同一常量（照 LOCK_AUTO_DELAYS 先例，杜绝再次漂移）。

**perm 预设锚定失效**
^[-dlbcps]... 的 ^ 锚定的是「转义序列之间的 text run 起点」而非行首，ls -l
多行输出只有第一行权限位上色；带颜色的 ls（run 以转义切开）完全不触发。
改为 (?<=^|\s)[-dlbcps][rwxstST-]{9}(?![rwxstST-])——用负向前瞻而不是
(?=\s|$) 是因为后者会让带 ACL `+` / macOS `@` 后缀的真实 ls -l 输出不再染色。
旧 pattern 登记进 LEGACY_BUILTIN_PATTERNS，存量安装下次启动自动升级。

**高亮 span 吃掉应用自身 SGR**
wrap 固定追加 \x1b[0m，把应用设的颜色一并清掉。改为 SgrState 跟踪并重放。
四条护栏（每条都踩过坑，详见 AGENTS.md）：
- reset 判定解析参数：ESC[00m/ESC[0;0m/ESC[0;32m（Go/Java 日志库常写）原先
  被追加进累积器，逐行增长直到撞上限，之后所有 span 恢复永久失效
- 回放闸门按序列条数而非字节数：同一个"单个前景色"长度差近 4 倍，按字节卡
  会砍掉真彩色却放过索引色
- 恢复串只插在可见间隙和最后一个 span 后：每 span 都重放会让 Kimi 这类全彩
  TUI（~19 span/行）把 9.5KB 输出膨胀到 40.8KB（4.30x），渲染线程实测卡
  18.4 秒。现为 3.05x 且长间隙着色正常
- 基准测试守门（膨胀 < 3.2x），改参数必须重跑

**CSI 私有参数导致整行失去高亮**
ESCAPE_RE 漏了 <>= 前缀与中间字节，\x1b[>4;1m(modifyOtherKeys)、
\x1b[<0;1;2M(SGR 鼠标)、\x1b[=1;1$y(DECRQM) 让整行成含裸 ESC 的文本，该行
之后所有关键词失去高亮（vim/tmux 常发）。

**超长行拖垮整段高亮**：一条 >4KB 的行让整个 text run 失去高亮。改为逐行降级。

**统计「最后写入者赢」**：模块级 totals 被各 pane 覆盖，设置页数据在窗格间
跳动。改为按 pane 实例 UUID 聚合（不能用 sessionId——SSH 分屏同一 session 挂
两个 pane，正好复制该 bug）。

## 新增能力

- **CJK 对齐三件套**：@xterm/addon-unicode11@0.10.0-beta.301（peer 恰好接受
  锁定的 6.1.0-beta.304，升 xterm 必须同步重配）、rescaleOverlappingGlyphs、
  cjkFontFamily 回退槽位。默认字体栈没有任何 CJK 字体，中文靠 Chromium 回退
  到比例字体导致列错位
- **字体名引号包裹**：quoteFontStack() 逐段判定（含反斜杠转义——只转义 " 会
  让尾部反斜杠把闭合引号转义掉，CSS 字符串不终止）
- **等宽徽标**：canvas measureText 逐字符采样，等宽排前
- **规则按行匹配**（lineAnchor → m flag）
- **命中提醒**（notify + onMatch 事件出口，60s 冷却，只显示规则名不显示原文）
- **可点击链接规则**（WezTerm hyperlink_rules 式，安全闸门在生成 span 时就
  丢弃非 http/https 目标）

## 其它

- 主题语义变量改为单一命名体系：semanticVars() 键就是最终 CSS 属性名，字面量
  键联合让拼错成为编译错误；删除 cssVarName()/semanticCssVars() 中间层
  （自定义属性名大小写敏感，转换被绕过会静默回落到深色兜底值）
- 删除死代码：automaticFontFallback 与顶层 overviewRuler 在 6.1.0-beta.304
  中均不存在，且移除了让任何伪造键都能通过 tsc 的 as 断言
- ReDoS 防护（MAX_PATTERN_LEN + 编辑器 backtracksBadly 实时探测）——注意这
  只是止血，(a+)+$ 配 30 字符实测仍卡 8.2 秒，根治需把正则执行挪进 Worker

测试 29 → 32（新增 font-stack、link-rules），全部通过；AGENTS.md 已同步。

tests/settings-store.mjs

@@ -20,6 +20,7 @@ import { mkdtempSync, readFileSync, existsSync, rmSync, writeFileSync } from 'no
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { createRequire } from 'node:module'
+import { DEFAULT_HIGHLIGHT_RULES } from '../src/shared/settings.ts'
 
 const require = createRequire(import.meta.url)
 const userData = mkdtempSync(join(tmpdir(), 'ot-settings-'))
@@ -60,6 +61,33 @@ for (const action of ['tray', 'exit', 'ask']) {
   ok(back === 'tray', `unknown closeAction falls back to 'tray' (got '${back}')`)
 }
 
+// ---- 1b. numeric font settings are clamped on load ---------------------------
+// xterm's constructor THROWS on lineHeight < 1 and the throw unmounts the whole
+// dockview pane. The value is persisted, so one bad entry bricked every start
+// until the file was hand-edited. The sanitizer must repair it instead.
+console.log('[font settings clamp]')
+{
+  const term = store.loadSettings().terminal
+  for (const [key, bad, want] of [
+    ['lineHeight', 0.85, 1],
+    ['lineHeight', 0.95, 1],
+    ['lineHeight', 9, 2],
+    ['fontSize', 4, 8],
+    ['fontSize', 99, 40],
+    ['letterSpacing', -3, 0],
+    ['letterSpacing', 50, 10]
+  ]) {
+    const back = (await roundTrip({ terminal: { ...term, [key]: bad } })).terminal[key]
+    ok(back === want, `${key} ${bad} is clamped to ${want} on load (got ${back})`)
+  }
+  // A legal value must survive untouched — the clamp is not a reset.
+  const legal = (await roundTrip({ terminal: { ...term, lineHeight: 1.35, fontSize: 18, letterSpacing: 1.5 } })).terminal
+  ok(
+    legal.lineHeight === 1.35 && legal.fontSize === 18 && legal.letterSpacing === 1.5,
+    'legal font values are preserved verbatim'
+  )
+}
+
 // ---- 2. highlight-rule repair ----------------------------------------------
 console.log('[highlight rules]')
 {
@@ -177,6 +205,51 @@ console.log('[value bands]')
   const dropped = (await roundTrip({ highlightRules: [rule({ basic: 'yes' })] })).highlightRules
   ok(dropped.length === 1 && dropped[0].basic === undefined, 'a non-boolean basic flag is dropped')
 }
+{
+  // lineAnchor: a rule anchored per line must come back still anchored, and a
+  // rule that never opted in must stay absent (not `false`) so settings.json
+  // stays compact.
+  const kept = (await roundTrip({ highlightRules: [rule({ lineAnchor: true })] })).highlightRules
+  ok(kept.length === 1 && kept[0].lineAnchor === true, 'a line-anchored rule keeps its flag')
+  const absent = (await roundTrip({ highlightRules: [rule()] })).highlightRules
+  ok(absent.length === 1 && absent[0].lineAnchor === undefined, 'a rule without the flag keeps it undefined')
+  const dropped = (await roundTrip({ highlightRules: [rule({ lineAnchor: 'yes' })] })).highlightRules
+  ok(
+    dropped.length === 1 && dropped[0].lineAnchor === undefined,
+    'a non-boolean lineAnchor flag is dropped'
+  )
+}
+{
+  // notify (per-rule "alert on hit"): same shape as lineAnchor — `true` survives,
+  // absent stays absent, anything non-boolean is dropped rather than coerced.
+  const kept = (await roundTrip({ highlightRules: [rule({ notify: true })] })).highlightRules
+  ok(kept.length === 1 && kept[0].notify === true, 'a notify rule keeps its flag')
+  const absent = (await roundTrip({ highlightRules: [rule()] })).highlightRules
+  ok(absent.length === 1 && absent[0].notify === undefined, 'a rule without the flag keeps it undefined')
+  const dropped = (await roundTrip({ highlightRules: [rule({ notify: 'yes' })] })).highlightRules
+  ok(
+    dropped.length === 1 && dropped[0].notify === undefined,
+    'a non-boolean notify flag is dropped'
+  )
+  // An explicit `false` is indistinct from absent after a save: the sanitizer
+  // normalises it away so settings.json never grows a dead key.
+  const off = (await roundTrip({ highlightRules: [rule({ notify: false })] })).highlightRules
+  ok(off.length === 1 && off[0].notify === undefined, 'notify: false is normalised to undefined')
+}
+{
+  // The preset rule set ships `secret` with the alert on (a leaked key is what
+  // the feature exists for) and nothing else flagged. Read from the preset
+  // constant rather than from disk: the user's stored set may legitimately have
+  // the flag off (see the upgrade note in the report), so this asserts the ship
+  // default, not the loaded result.
+  const flagged = DEFAULT_HIGHLIGHT_RULES.filter((r) => r.notify === true).map((r) => r.id)
+  ok(
+    flagged.length === 1 && flagged[0] === 'secret',
+    `only the secret preset notifies by default (got ${flagged.join(',')})`
+  )
+  const secret = DEFAULT_HIGHLIGHT_RULES.find((r) => r.id === 'secret')
+  ok(secret?.basic === true && secret?.notify === true, 'the secret preset notifies in both highlight modes')
+}
 {
   for (const on of [true, false]) {
     const back = await roundTrip({
@@ -196,6 +269,26 @@ console.log('[value bands]')
     )
   }
 }
+{
+  // cjkFontFamily: the CJK fallback slot appended to the font stack. Empty is
+  // the default (append nothing, unchanged behaviour); a real family name and
+  // a non-string — the settings file is hand-editable, and a number here would
+  // otherwise reach `appendCjk` and be concatenated into the stack as text.
+  ok(store.loadSettings().terminal.cjkFontFamily === '', 'the CJK fallback defaults to empty')
+  for (const cjk of ['Microsoft YaHei', "'Noto Sans CJK SC'", '']) {
+    const back = await roundTrip({
+      terminal: { ...store.loadSettings().terminal, cjkFontFamily: cjk }
+    })
+    ok(back.terminal.cjkFontFamily === cjk, `CJK fallback '${cjk}' survives the round trip`)
+  }
+  const dropped = await roundTrip({
+    terminal: { ...store.loadSettings().terminal, cjkFontFamily: 42 }
+  })
+  ok(
+    dropped.terminal.cjkFontFamily === '',
+    `a non-string CJK fallback is dropped back to empty (got '${dropped.terminal.cjkFontFamily}')`
+  )
+}
 {
   const rules = [rule({ id: 'keep-1' }), rule({ id: 'keep-2' })]
   await roundTrip({ highlightRules: rules })