feat(settings): replicate the WorkBuddy appearance panel and dark theme (TODO 11)

Recover the WorkBuddy 5.8.3 appearance page from REA evidence (appearance-DMmhwsxq.css + tokens-Df-i-zsO.css): 44 recovered .appearance-* rules, scoped light/dark tokens, original geometry (panel [232,40,638,640], preview 634x317, grid 634x218.391, cards 118.797x79.188) and the two REA-exported preview images with provenance sha256.

Wire the panel into SettingsDialog with only the requested light/dark cards, add scoped tokens to the settings shell so the dark theme no longer renders a white window with near-white text, and verify with scripts/verify-appearance-settings.cjs (21 assertions: geometry, instant switch, cross-window sync, persistence, dark/light surface sampling with contrast >= 4.5, no renderer errors). Update the legacy nav/account/desktop appearance verifiers to the new .appearance-card selectors.

scripts/rea/recover-appearance-panel.mjs

@@ -0,0 +1,80 @@
+// Recover only already-retained REA CSS; never access the installed application here.
+//
+// Source: REA evidence ev_24ab58532d4ece0d79f35c8c7d4cb14f5611a7405cdf747c4698e6184bea7d99
+// (WorkBuddy 5.8.3 设置 → 外观), 模块样式表 appearance-DMmhwsxq.css（原版懒加载，只有进入外观页才请求）。
+// 面板 DOM 与几何来自同一批 REA 证据 `.tmp/todo11-wb-appearance/layout.json`：
+// .appearance-panel [232,40,638,640]、.appearance-preview 634×317、卡片网格 5 列 118.8×101.2、卡片 118.8×79.2。
+import fs from 'node:fs/promises'
+import { createHash } from 'node:crypto'
+import postcss from 'postcss'
+const sha = value => createHash('sha256').update(value).digest('hex')
+const evidenceId = 'ev_24ab58532d4ece0d79f35c8c7d4cb14f5611a7405cdf747c4698e6184bea7d99'
+const evidence = JSON.parse(await fs.readFile(`.tmp/rea-css-evidence/${evidenceId}.json`, 'utf8'))
+if (evidence.evidence_id !== evidenceId) throw new Error('REA identity mismatch')
+const module = evidence.normalized_result.styles.items.find(item => /appearance-DMmhwsxq\.css$/.test(item.file_path))
+if (!module) throw new Error('Appearance module CSS is absent from the evidence')
+const moduleCss = module.source.artifact.text
+const moduleSha = sha(moduleCss)
+if (moduleSha !== 'af58cb3134d3e6c474424f6d718daa8f5be0c6e29d40aa5f9f80c14b3ffbbbd2') throw new Error('Appearance module CSS changed')
+const tokens = await fs.readFile('.tmp/rea-css-recovered/tokens-Df-i-zsO.css', 'utf8')
+const tokensSha = sha(tokens)
+if (tokensSha !== '13f2bf82c96e5167a7d7098e36950c6c22c475b3337dbb8bb29ad2fe79cde696') throw new Error('Tokens CSS changed')
+
+// 原版外观面板自己的 token 定义（--wb-text-strong 等）在 tokens 样式表里，按组件作用域复制一份。
+const lightTokens = new Map()
+const darkTokens = new Map()
+for (const rule of postcss.parse(tokens).nodes) {
+  if (rule.type !== 'rule') continue
+  const selectors = rule.selectors ?? []
+  const dark = selectors.some(selector => selector.includes('[data-theme=dark]'))
+  const light = selectors.some(selector => selector.trim() === ':root')
+  if (!dark && !light) continue
+  for (const node of rule.nodes ?? []) {
+    if (node.type !== 'decl' || !node.prop.startsWith('--')) continue
+    if (dark) darkTokens.set(node.prop, node.value)
+    if (light) lightTokens.set(node.prop, node.value)
+  }
+}
+
+// 只保留外观面板相关规则；同时把原版的深色选择器（.dark / [data-cb-theme=dark]）改写成 YCode 的 [data-theme=dark]。
+const darkSelector = /(^|[\s,>+~])\.dark\b|\[data-cb-theme=dark\]/g
+function project(node) {
+  if (node.type === 'rule') {
+    const selectors = []
+    for (const selector of node.selectors) {
+      if (!/\.appearance-/.test(selector)) continue
+      const mapped = selector.replace(darkSelector, (match, prefix) => `${prefix ?? ''}[data-theme=dark]`)
+      if (!selectors.includes(mapped)) selectors.push(mapped)
+    }
+    return selectors.length ? node.clone({ selector: selectors.join(',') }) : null
+  }
+  if (node.type === 'atrule' && node.nodes) {
+    const nodes = node.nodes.map(project).filter(Boolean)
+    return nodes.length ? node.clone({ nodes }) : null
+  }
+  return null
+}
+const root = postcss.root({ nodes: postcss.parse(moduleCss).nodes.map(project).filter(Boolean) })
+const referenced = new Set()
+const collect = (text) => { for (const match of text.matchAll(/var\(\s*(--[\w-]+)/g)) referenced.add(match[1]) }
+collect(root.toString())
+for (let depth = 0; depth < 6; depth++) {
+  const before = referenced.size
+  for (const name of [...referenced]) {
+    const value = lightTokens.get(name) ?? darkTokens.get(name)
+    if (typeof value === 'string') collect(value)
+  }
+  if (referenced.size === before) break
+}
+const missing = [...referenced].filter(name => !lightTokens.has(name))
+if (missing.length) console.log(`Tokens missing from light root scope: ${missing.join(', ')}`)
+const pick = (map) => new Map([...referenced].filter(name => map.has(name)).map(name => [name, map.get(name)]))
+const scope = (name, map) => `.${name}{${[...map].map(([property, value]) => `${property}:${value}`).join(';')}}`
+const scopedTokens = `${scope('appearance-panel', pick(lightTokens))}\n:root[data-theme=dark] ${scope('appearance-panel', pick(darkTokens))}\n`
+const css = `/* REA ${evidenceId}; appearance-DMmhwsxq.css sha256=${moduleSha}; tokens sha256=${tokensSha}. */\n${root.toString()}\n${scopedTokens}`
+await fs.writeFile('src/renderer/src/components/source-appearance-panel-recovered.css', css)
+const rules = []
+root.walkRules(rule => rules.push(rule.selector))
+console.log(`Recovered ${rules.length} appearance rules (${css.length} bytes); scoped ${pick(lightTokens).size} light / ${pick(darkTokens).size} dark tokens`)
+console.log(rules.slice(0, 10).join('\n'))
+if (rules.length < 20) throw new Error('Unexpectedly few appearance rules')