diff --git a/web/package-lock.json b/web/package-lock.json
index e84a22f..87fbded 100644
--- a/web/package-lock.json
+++ b/web/package-lock.json
@@ -24,6 +24,7 @@
         "remark-gfm": "^4.0.1"
       },
       "devDependencies": {
+        "@codemirror/commands": "^6.11.0",
         "@tailwindcss/typography": "^0.5.19",
         "@tailwindcss/vite": "^4.3.3",
         "@testing-library/dom": "^10.4.0",
diff --git a/web/package.json b/web/package.json
index cc7283a..3cc377b 100644
--- a/web/package.json
+++ b/web/package.json
@@ -27,6 +27,7 @@
     "remark-gfm": "^4.0.1"
   },
   "devDependencies": {
+    "@codemirror/commands": "^6.11.0",
     "@tailwindcss/typography": "^0.5.19",
     "@tailwindcss/vite": "^4.3.3",
     "@testing-library/dom": "^10.4.0",
diff --git a/web/tests/editor-boundaries.test.ts b/web/tests/editor-boundaries.test.ts
new file mode 100644
index 0000000..8bfbf94
--- /dev/null
+++ b/web/tests/editor-boundaries.test.ts
@@ -0,0 +1,449 @@
+// P3 加固回归（方案 §7.2 / §7.3 / §7.4、§12.4）：
+// 1) 文首边界：文档以标题/列表/任务/围栏/水平线开头；
+// 2) 文末边界：文档以水平线/图片/围栏/任务结尾（对应 CM issue #625「文末块 widget 消失」一类的回归面）；
+// 3) 跨原子区间选区：全选替换、跨隐藏标记的选区替换、只选中可见内容时标记不被破坏；
+// 4) 不变量：原子区间不跨行、有序不重叠、不含可编辑内容、隐藏标记必在原子区间内；
+// 5) 性能基准：3000 行文档的装饰计算耗时（§7.4 目标 < 16ms/帧）。
+//
+// 说明：happy-dom 下 CodeMirror 可以真实创建 EditorView 并渲染装饰 DOM，
+// 因此本文件用真实 view 断言，而不是只看纯函数输出。
+
+import { afterEach, describe, expect, it } from 'vitest'
+import { EditorState } from '@codemirror/state'
+import { EditorView } from '@codemirror/view'
+import { syntaxTree } from '@codemirror/language'
+import { markdown, markdownLanguage } from '@codemirror/lang-markdown'
+import { deleteCharBackward } from '@codemirror/commands'
+import { livePreview } from '../src/editor/livePreview'
+import { collectSpecs } from '../src/editor/syntax'
+import { buildDecorations, visibleSyntaxTree } from '../src/editor/decorations'
+
+const views: EditorView[] = []
+
+function mount(doc: string, anchor = 0, focus = true): EditorView {
+  const state = EditorState.create({
+    doc,
+    selection: { anchor },
+    extensions: [markdown({ base: markdownLanguage }), livePreview()],
+  })
+  const parent = document.createElement('div')
+  document.body.appendChild(parent)
+  const view = new EditorView({ state, parent })
+  if (focus) view.focus()
+  views.push(view)
+  return view
+}
+
+/** 通过公开 facet 读出当前生效的原子区间（升序）。 */
+function atomicRanges(view: EditorView): Array<[number, number]> {
+  const out: Array<[number, number]> = []
+  for (const fn of view.state.facet(EditorView.atomicRanges)) {
+    fn(view).between(0, view.state.doc.length, (from, to) => {
+      out.push([from, to])
+    })
+  }
+  return out.sort((a, b) => a[0] - b[0] || a[1] - b[1])
+}
+
+function lineTexts(view: EditorView): string[] {
+  return [...view.dom.querySelectorAll('.cm-line')].map((el) => el.textContent ?? '')
+}
+
+function replaceDoc(view: EditorView, from: number, to: number, insert: string): void {
+  view.dispatch({ changes: { from, to, insert }, selection: { anchor: from + insert.length } })
+}
+
+afterEach(() => {
+  for (const v of views.splice(0)) v.destroy()
+  document.body.innerHTML = ''
+})
+
+describe('文首边界', () => {
+  it('以标题开头：标记隐藏、整行 h1、标记区间原子化', () => {
+    const doc = '# 标题\n\n正文'
+    const view = mount(doc, doc.length)
+    expect(lineTexts(view)[0]).toBe('标题')
+    expect(view.dom.querySelectorAll('.cm-md-h1')).toHaveLength(1)
+    expect(atomicRanges(view)).toContainEqual([0, 2])
+  })
+
+  it('光标停在文档起点回退：不抛错、内容不变、光标不越界', () => {
+    const doc = '# 标题\n\n正文'
+    const view = mount(doc, 0)
+    deleteCharBackward(view)
+    expect(view.state.doc.toString()).toBe(doc)
+    expect(view.state.selection.main.head).toBe(0)
+  })
+
+  it('以任务项开头：复选框渲染在文首、标记让位、列表标记原子化', () => {
+    const doc = '- [ ] 第一项\n\n正文'
+    const view = mount(doc, doc.length)
+    expect(view.dom.querySelectorAll('.cm-md-task')).toHaveLength(1)
+    expect(lineTexts(view)[0]).not.toContain('-')
+    expect(atomicRanges(view)).toContainEqual([0, 2]) // `- `
+  })
+
+  it('以围栏开头：语言标签在文首渲染，块内不解析行内语法', () => {
+    const doc = '```js\n**原样**\n```\n\n正文'
+    const view = mount(doc, doc.length)
+    expect(view.dom.querySelector('.cm-md-fence-lang')?.textContent).toBe('js')
+    expect(view.dom.querySelectorAll('.cm-md-strong')).toHaveLength(0)
+  })
+
+  it('以水平线开头：hr widget 渲染在文首', () => {
+    const doc = '---\n\n正文'
+    const view = mount(doc, doc.length)
+    expect(view.dom.querySelectorAll('.cm-md-hr')).toHaveLength(1)
+    expect(lineTexts(view)[0]).toBe('')
+  })
+})
+
+describe('文末边界', () => {
+  it('以水平线结尾：hr widget 渲染在最后一行', () => {
+    const doc = '正文\n\n---'
+    const view = mount(doc, 0)
+    expect(view.dom.querySelectorAll('.cm-md-hr')).toHaveLength(1)
+    const last = lineTexts(view).at(-1)
+    expect(last).toBe('')
+    expect(atomicRanges(view)).toContainEqual([doc.length - 3, doc.length])
+  })
+
+  it('文档只有一条水平线：不抛错且渲染 hr', () => {
+    const view = mount('---', 0)
+    expect(view.state.doc.length).toBe(3)
+    expect(view.dom.querySelectorAll('.cm-md-hr')).toHaveLength(1)
+  })
+
+  it('以图片结尾：img widget 在文末，src 与 alt 正确', () => {
+    const doc = '正文\n\n![配图](/api/images/9)'
+    const view = mount(doc, 0)
+    const img = view.dom.querySelector('.cm-md-image') as HTMLImageElement | null
+    expect(img).not.toBeNull()
+    expect(img?.getAttribute('src')).toBe('/api/images/9')
+    expect(img?.getAttribute('alt')).toBe('配图')
+  })
+
+  it('以围栏结尾：闭围栏隐藏，末行仍带 fenced 类', () => {
+    const doc = '正文\n\n```js\nconst a = 1\n```'
+    const view = mount(doc, 0)
+    expect(lineTexts(view).at(-1)).toBe('')
+    expect(lineTexts(view).at(-2)).toBe('const a = 1')
+    expect(view.dom.querySelectorAll('.cm-md-fenced')).toHaveLength(3)
+  })
+
+  it('以任务项结尾：复选框渲染在最后一行', () => {
+    const doc = '正文\n\n- [x] 末项'
+    const view = mount(doc, 0)
+    const tasks = view.dom.querySelectorAll('.cm-md-task')
+    expect(tasks).toHaveLength(1)
+    expect((tasks[0] as HTMLInputElement).checked).toBe(true)
+    expect(lineTexts(view).at(-1)).not.toContain('[x]')
+  })
+
+  it('文末追加内容后装饰正确重建（不给文末留残影）', () => {
+    const doc = '正文\n\n---'
+    const view = mount(doc, 0)
+    view.dispatch({ changes: { from: doc.length, insert: '\n\n## 新小节\n\n新段落' } })
+    expect(lineTexts(view).some((t) => t === '新小节')).toBe(true)
+    expect(view.dom.querySelectorAll('.cm-md-h2')).toHaveLength(1)
+    expect(view.dom.querySelectorAll('.cm-md-hr')).toHaveLength(1)
+  })
+
+  it('文末整体清空（全选删除）不抛错', () => {
+    const doc = '# 标题\n\n- A\n\n![x](/api/images/1)\n\n---\n\n```js\nx\n```\n'
+    const view = mount(doc, 0)
+    replaceDoc(view, 0, doc.length, '')
+    expect(view.state.doc.toString()).toBe('')
+  })
+})
+
+describe('跨原子区间选区', () => {
+  const doc = '# 标题\n\n- 甲\n\n段落 **粗体** 结尾\n'
+
+  it('全选替换：跨多个隐藏标记的选区可整体替换', () => {
+    const view = mount(doc, doc.length)
+    replaceDoc(view, 0, doc.length, 'X')
+    expect(view.state.doc.toString()).toBe('X')
+  })
+
+  it('选区横跨隐藏标记：替换结果不残留标记碎片', () => {
+    const view = mount(doc, doc.length)
+    const boldStart = doc.indexOf('**')
+    replaceDoc(view, 0, boldStart + 2, '替换')
+    expect(view.state.doc.toString()).toBe('替换粗体** 结尾\n')
+  })
+
+  it('只选中可见内容时替换，标记完整保留', () => {
+    const doc2 = '段落 **粗体** 结尾'
+    const view = mount(doc2, doc2.length)
+    const from = doc2.indexOf('粗体')
+    replaceDoc(view, from, from + 2, 'X')
+    expect(view.state.doc.toString()).toBe('段落 **X** 结尾')
+  })
+
+  it('选中「标记 + 内容 + 标记」整体删除后，只剩两侧文字', () => {
+    const doc2 = '段落 **粗体** 结尾'
+    const view = mount(doc2, doc2.length)
+    replaceDoc(view, 3, 9, '')
+    expect(view.state.doc.toString()).toBe('段落  结尾')
+    expect(view.dom.querySelectorAll('.cm-md-strong')).toHaveLength(0)
+  })
+
+  it('删除跨行的选区（含列表行与引用行）后装饰重建正确', () => {
+    const doc2 = '前言\n\n- 甲\n- 乙\n\n> 引用\n\n结尾'
+    const view = mount(doc2, doc2.length)
+    replaceDoc(view, 2, doc2.indexOf('结尾'), '')
+    const left = view.state.doc.toString()
+    expect(left).toContain('前言')
+    expect(left).toContain('结尾')
+    expect(left).not.toContain('甲')
+    expect(left).not.toContain('引用')
+    expect(view.dom.querySelectorAll('.cm-md-bullet')).toHaveLength(0)
+    expect(view.dom.querySelectorAll('.cm-md-quote-bar')).toHaveLength(0)
+  })
+})
+
+describe('装饰层不变量', () => {
+  const docs = [
+    '# 标题\n\n正文 **粗** 与 *斜* 与 `码` 与 [链](https://a.example)\n',
+    '- [ ] 待办\n- [x] 完成\n  - 嵌套\n1. 有序\n',
+    '> 一\n> > 二\n\n---\n\n```js\ncode\n```\n\n| a | b |\n| --- | --- |\n| 1 | 2 |\n',
+    '![图](/api/images/1)\n\n结尾\n',
+  ]
+
+  it('原子区间不跨行（CM6 硬性约束）', () => {
+    for (const doc of docs) {
+      for (const anchor of [0, doc.length]) {
+        const view = mount(doc, anchor)
+        for (const [from, to] of atomicRanges(view)) {
+          expect(view.state.doc.lineAt(from).number).toBe(view.state.doc.lineAt(to).number)
+        }
+      }
+    }
+  })
+
+  it('原子区间有序且互不重叠', () => {
+    for (const doc of docs) {
+      const view = mount(doc, doc.length)
+      const ranges = atomicRanges(view)
+      for (let i = 1; i < ranges.length; i++) {
+        expect(ranges[i][0]).toBeGreaterThanOrEqual(ranges[i - 1][1])
+      }
+    }
+  })
+
+  it('隐藏标记一定落在原子区间内（退格可整段删净）', () => {
+    const doc = '# 标题\n\n- 甲\n> 乙\n\n**粗**\n'
+    const view = mount(doc, doc.length)
+    const ranges = atomicRanges(view)
+    const tree = syntaxTree(view.state)
+    for (const spec of collectSpecs(tree, view.state.doc, 0, doc.length)) {
+      if (spec.kind !== 'hide') continue
+      expect(ranges).toContainEqual([spec.from, spec.to])
+    }
+  })
+
+  it('强调 / 行内代码 / 链接的内容区间绝不被原子化（§4.2）', () => {
+    const doc = '文字 **粗体** 与 `代码` 与 [链接](https://a.example) 结束\n'
+    const view = mount(doc, doc.length)
+    const ranges = atomicRanges(view)
+    const tree = syntaxTree(view.state)
+    const contentSpecs = collectSpecs(tree, view.state.doc, 0, doc.length).filter(
+      (s) => s.kind === 'mark' && ['cm-md-strong', 'cm-md-code', 'cm-md-link'].includes(s.cls),
+    )
+    expect(contentSpecs).toHaveLength(3)
+    for (const spec of contentSpecs) {
+      for (const [from, to] of ranges) {
+        expect(spec.from >= to || spec.to <= from).toBe(true)
+      }
+    }
+  })
+
+  it('reveal 契约：光标进入某行后该行原子区间消失，离开后恢复', () => {
+    const doc = '# 标题\n\n正文 **粗** 结束\n'
+    const view = mount(doc, doc.length) // 光标在末行
+    expect(atomicRanges(view)).toContainEqual([0, 2])
+    expect(lineTexts(view)[0]).toBe('标题')
+
+    view.dispatch({ selection: { anchor: 1 } }) // 光标进入标题行
+    expect(atomicRanges(view)).not.toContainEqual([0, 2])
+    expect(lineTexts(view)[0]).toBe('# 标题')
+
+    view.dispatch({ selection: { anchor: doc.length } }) // 离开
+    expect(atomicRanges(view)).toContainEqual([0, 2])
+    expect(lineTexts(view)[0]).toBe('标题')
+  })
+
+  it('失焦（未聚焦）时不展开任何行，整篇按渲染态呈现', () => {
+    const doc = '# 标题\n\n正文\n'
+    const view = mount(doc, 5, false) // 不调用 focus()
+    expect(view.hasFocus).toBe(false)
+    expect(lineTexts(view)[0]).toBe('标题')
+    expect(atomicRanges(view)).toContainEqual([0, 2])
+  })
+})
+
+describe('长文档：惰性解析与装饰补齐', () => {
+  function buildDoc(lines: number): string {
+    const out: string[] = []
+    for (let i = 0; i < lines; i++) {
+      if (i % 7 === 0) out.push(`## 小节 ${i}`)
+      else if (i % 5 === 0) out.push(`- 条目 ${i} 带 **粗体** 与 \`代码\` 和 [链接](https://a.example/${i})`)
+      else if (i % 11 === 0) out.push('> 引用一行内容')
+      else out.push(`第 ${i} 行正文，包含 **强调**、*斜体*、\`行内代码\` 与 [链接](https://a.example/${i})。`)
+    }
+    return out.join('\n')
+  }
+
+  const doc = buildDoc(3000)
+  const state = EditorState.create({ doc, extensions: [markdown({ base: markdownLanguage })] })
+
+  it('如实记录：syntaxTree 对长文档只返回已解析的前段（lezer 惰性增量）', () => {
+    const partial = syntaxTree(state).length
+    // eslint-disable-next-line no-console
+    console.log(`[parse] 3000 行文档（${doc.length} 字符）：syntaxTree 首次仅覆盖 ${partial} 字符`)
+    expect(partial).toBeLessThan(doc.length)
+    expect(partial).toBeGreaterThan(0)
+  })
+
+  it('visibleSyntaxTree 在给定预算内把可见区间补齐，装饰不再缺失', () => {
+    const win = { from: state.doc.line(1500).from, to: state.doc.line(1600).to }
+    const cold = syntaxTree(state).length
+    const tree = visibleSyntaxTree(state, [win], 2000)
+    // eslint-disable-next-line no-console
+    console.log(`[parse] 补解析窗口 [${win.from}, ${win.to}]：树覆盖 ${cold} → ${tree.length}`)
+    expect(tree.length).toBeGreaterThanOrEqual(win.to)
+    const { decorations } = buildDecorations(state, [win], false, tree)
+    expect(decorations.size).toBeGreaterThan(50)
+  })
+
+  it('预算受限时越界区间保持源码态，且不会抛错（等解析推进后自动补齐）', () => {
+    const win = { from: state.doc.line(2900).from, to: state.doc.line(2950).to }
+    const tree = visibleSyntaxTree(state, [win], 20)
+    const { decorations } = buildDecorations(state, [win], false, tree)
+    if (tree.length < win.from) expect(decorations.size).toBe(0)
+    else expect(decorations.size).toBeGreaterThanOrEqual(0)
+  })
+
+  it('装饰不会越过已解析边界（避免对半截节点做出错误渲染）', () => {
+    const partialLen = syntaxTree(state).length
+    const { decorations } = buildDecorations(state, [{ from: 0, to: doc.length }], false, syntaxTree(state))
+    let maxTo = 0
+    decorations.between(0, doc.length, (_f, to) => {
+      if (to > maxTo) maxTo = to
+    })
+    expect(maxTo).toBeLessThanOrEqual(partialLen)
+  })
+
+  it('光标行远在可见区间之外时仍被装饰（CM 会单独渲染选区所在块）', () => {
+    // 选区停在文档开头（第 1 行是 `## 小节 0`），可见区间取远端窗口
+    const win = { from: state.doc.line(2500).from, to: state.doc.line(2510).to }
+    const { decorations } = buildDecorations(state, [win], false)
+    let startLineClass: string | null = null
+    decorations.between(0, state.doc.line(1).to, (_f, _t, value) => {
+      if (typeof value.spec.class === 'string') startLineClass = value.spec.class
+    })
+    expect(startLineClass).toBe('cm-md-h2')
+
+    // 远端窗口同样被装饰：补解析 + 采集覆盖了两段
+    let farCount = 0
+    decorations.between(win.from, win.to, () => {
+      farCount++
+    })
+    expect(farCount).toBeGreaterThan(0)
+  })
+})
+
+describe('性能基准（§7.4：3000 行文档单帧 < 16ms）', () => {
+  function buildDoc(lines: number): string {
+    const out: string[] = []
+    for (let i = 0; i < lines; i++) {
+      if (i % 7 === 0) out.push(`## 小节 ${i}`)
+      else if (i % 5 === 0) out.push(`- 条目 ${i} 带 **粗体** 与 \`代码\` 和 [链接](https://a.example/${i})`)
+      else if (i % 11 === 0) out.push('> 引用一行内容')
+      else out.push(`第 ${i} 行正文，包含 **强调**、*斜体*、\`行内代码\` 与 [链接](https://a.example/${i})。`)
+    }
+    return out.join('\n')
+  }
+
+  const median = (xs: number[]): number => xs.slice().sort((a, b) => a - b)[Math.floor(xs.length / 2)]
+
+  it('视口窗口（约 100 行）装饰计算中位数 < 16ms', () => {
+    const doc = buildDoc(3000)
+    const state = EditorState.create({ doc, extensions: [markdown({ base: markdownLanguage })] })
+    const win = { from: state.doc.line(1500).from, to: state.doc.line(1600).to }
+    const tree = visibleSyntaxTree(state, [win], 5000) // 预热到窗口可用
+
+    const samples: number[] = []
+    for (let i = 0; i < 40; i++) {
+      const t0 = performance.now()
+      const specs = collectSpecs(tree, state.doc, win.from, win.to)
+      samples.push(performance.now() - t0)
+      expect(specs.length).toBeGreaterThan(50)
+    }
+    const med = median(samples)
+    // eslint-disable-next-line no-console
+    console.log(
+      `[perf] 3000 行 / 视口 100 行：collectSpecs 中位数 ${med.toFixed(3)}ms，p95 ${median(samples.slice().sort((a, b) => a - b).slice(-2)).toFixed(3)}ms，最大 ${Math.max(...samples).toFixed(3)}ms`,
+    )
+    expect(med).toBeLessThan(16)
+  })
+
+  it('整篇作为单一可见区间（最坏情况）仍远低于一帧量级', () => {
+    const doc = buildDoc(3000)
+    const state = EditorState.create({ doc, extensions: [markdown({ base: markdownLanguage })] })
+    const tree = visibleSyntaxTree(state, [{ from: 0, to: doc.length }], 10000)
+    expect(tree.length).toBe(doc.length)
+
+    const samples: number[] = []
+    for (let i = 0; i < 10; i++) {
+      const t0 = performance.now()
+      const specs = collectSpecs(tree, state.doc, 0, doc.length)
+      samples.push(performance.now() - t0)
+      expect(specs.length).toBeGreaterThan(3000)
+    }
+    const med = median(samples)
+    // eslint-disable-next-line no-console
+    console.log(
+      `[perf] 3000 行 / 全篇单区间：collectSpecs 中位数 ${med.toFixed(3)}ms，最大 ${Math.max(...samples).toFixed(3)}ms`,
+    )
+    expect(med).toBeLessThan(100)
+  })
+
+  it('冷启动成本实测：首次强制解析整篇 3000 行', () => {
+    const doc = buildDoc(3000)
+    const state = EditorState.create({ doc, extensions: [markdown({ base: markdownLanguage })] })
+    const t0 = performance.now()
+    const tree = visibleSyntaxTree(state, [{ from: 0, to: doc.length }], 10000)
+    const ms = performance.now() - t0
+    // eslint-disable-next-line no-console
+    console.log(`[perf] 3000 行（${doc.length} 字符）全量解析耗时 ${ms.toFixed(1)}ms（树覆盖 ${tree.length} 字符）`)
+    expect(tree.length).toBe(doc.length)
+  })
+
+  it('最坏选区：Cmd+A 整篇选区 + 视口窗口，装饰构建仍在一帧预算内', () => {
+    const doc = buildDoc(3000)
+    // 整篇选区 + 聚焦（触发 reveal，展开区间多达 3000 个）
+    const state = EditorState.create({
+      doc,
+      selection: { anchor: 0, head: doc.length },
+      extensions: [markdown({ base: markdownLanguage })],
+    })
+    const win = { from: state.doc.line(1500).from, to: state.doc.line(1560).to }
+    const tree = visibleSyntaxTree(state, [win], 10000)
+
+    const samples: number[] = []
+    for (let i = 0; i < 10; i++) {
+      const t0 = performance.now()
+      const { decorations } = buildDecorations(state, [win], true, tree)
+      samples.push(performance.now() - t0)
+      expect(decorations.size).toBeGreaterThan(0)
+    }
+    const med = median(samples)
+    // eslint-disable-next-line no-console
+    console.log(
+      `[perf] 最坏选区（整篇选中）：buildDecorations 中位数 ${med.toFixed(3)}ms，最大 ${Math.max(...samples).toFixed(3)}ms`,
+    )
+    expect(med).toBeLessThan(16)
+  })
+})
diff --git a/web/tests/editor-live-preview.test.ts b/web/tests/editor-live-preview.test.ts
new file mode 100644
index 0000000..e6d85c3
--- /dev/null
+++ b/web/tests/editor-live-preview.test.ts
@@ -0,0 +1,311 @@
+// 即时渲染装饰层单测（方案 §8）：
+// 1) syntax.ts 区间识别：标题 / 强调 / 行内代码 / 链接 / 图片 / 引用 / 列表 /
+//    任务 / 围栏 / 水平线 / 表格，覆盖嵌套、代码块内不解析、中文标点；
+// 2) reveal.ts：行粒度展开只撤销「标记替代物」，样式类保留；
+// 3) decorations.ts：白名单外的图片 src 退回源码文本；widget DOM 无注入面。
+import { describe, expect, it } from 'vitest'
+import { EditorState } from '@codemirror/state'
+import { syntaxTree } from '@codemirror/language'
+import { markdown, markdownLanguage } from '@codemirror/lang-markdown'
+import { collectSpecs, type Spec } from '../src/editor/syntax'
+import { activeLineRanges, applyReveal, intersectsAny, selectionEndpointLines } from '../src/editor/reveal'
+import { buildDecorations, IMAGE_SRC_ALLOW } from '../src/editor/decorations'
+import { FenceLangWidget, ImageWidget, TaskWidget } from '../src/editor/widgets'
+
+function makeState(src: string, cursor = 0) {
+  return EditorState.create({
+    doc: src,
+    selection: { anchor: cursor },
+    extensions: [markdown({ base: markdownLanguage })],
+  })
+}
+
+/** 采集全文档 specs，按位置排序，便于断言。 */
+function collect(src: string): Spec[] {
+  const state = makeState(src)
+  const specs = collectSpecs(syntaxTree(state), state.doc, 0, src.length)
+  return specs.slice().sort((a, b) => a.from - b.from || a.to - b.to)
+}
+
+/** 断言用的简化视图：`kind:原文`。 */
+function digest(src: string, specs = collect(src)): string[] {
+  return specs.map((s) => {
+    if (s.kind === 'line') return `line(#${s.line}:${s.cls})`
+    const text = src.slice(s.from, s.to)
+    const extra =
+      s.kind === 'bullet' || s.kind === 'quote' ? ` d${s.depth}` : s.kind === 'mark' ? ` ${s.cls}` : ''
+    return `${s.kind}(${JSON.stringify(text)}${extra})`
+  })
+}
+
+describe('syntax.ts 区间识别', () => {
+  it('标题：隐藏 `# `，整行上 h1 类，行内语法继续解析', () => {
+    const src = '# 标题 **粗**'
+    const d = digest(src)
+    expect(d).toContain('line(#1:cm-md-h1)')
+    expect(d).toContain('hide("# ")')
+    expect(d).toContain('hide("**")')
+    expect(d).toContain('mark("粗" cm-md-strong)')
+  })
+
+  it('强调：隐藏定界符，内容上样式（含嵌套）', () => {
+    const d = digest('a **粗** b *斜* c ~~删~~')
+    expect(d).toEqual([
+      'hide("**")',
+      'mark("粗" cm-md-strong)',
+      'hide("**")',
+      'hide("*")',
+      'mark("斜" cm-md-em)',
+      'hide("*")',
+      'hide("~~")',
+      'mark("删" cm-md-del)',
+      'hide("~~")',
+    ])
+  })
+
+  it('行内代码：隐藏反引号，内容不二次解析（`*x*` 保持字面量）', () => {
+    const d = digest('`*x*`')
+    expect(d).toEqual(['hide("`")', 'mark("*x*" cm-md-code)', 'hide("`")'])
+  })
+
+  it('链接：隐藏 `[` 与 `](url)`，文本上链接类；不产出 <a>', () => {
+    const src = '[标题](https://a.example/x)'
+    const d = digest(src)
+    expect(d).toEqual(['hide("[")', 'mark("标题" cm-md-link)', 'hide("](https://a.example/x)")'])
+  })
+
+  it('图片：整段替换为 image spec，带 alt 与 src', () => {
+    const specs = collect('![配图](/api/images/7)')
+    const img = specs.find((s) => s.kind === 'image')
+    expect(img).toMatchObject({ alt: '配图', src: '/api/images/7' })
+  })
+
+  it('引用：每个 QuoteMark 一个竖线 widget，嵌套深度递增，同行去重加 cm-md-quote', () => {
+    const src = '> 一\n> > 二'
+    const d = digest(src)
+    expect(d.filter((x) => x.startsWith('quote('))).toEqual(['quote(">" d1)', 'quote(">" d1)', 'quote(">" d2)'])
+    // 第 2 行有两个 QuoteMark，原样各出一条行类；构建阶段按键去重后每行只剩一条
+    expect(d.filter((x) => x === 'line(#1:cm-md-quote)')).toHaveLength(1)
+    expect(d.filter((x) => x === 'line(#2:cm-md-quote)')).toHaveLength(2)
+
+    const state = makeState(src)
+    const { decorations } = buildDecorations(state, [{ from: 0, to: src.length }], false)
+    const lineClasses: unknown[] = []
+    decorations.between(0, src.length, (_f, _t, value) => {
+      if (value.spec.class) lineClasses.push(value.spec.class)
+    })
+    expect(lineClasses.filter((c) => c === 'cm-md-quote')).toHaveLength(2)
+  })
+
+  it('无序列表：圆点 widget 覆盖「标记 + 空格」，嵌套深度递增', () => {
+    const d = digest('- A\n  - B')
+    expect(d.filter((x) => x.startsWith('bullet('))).toEqual(['bullet("- " d1)', 'bullet("- " d2)'])
+  })
+
+  it('有序列表：保留数字，仅上样式，不替换不原子（决策 E3）', () => {
+    const d = digest('1. 一\n2. 二')
+    expect(d).toEqual(['mark("1." cm-md-ol-mark)', 'mark("2." cm-md-ol-mark)'])
+  })
+
+  it('任务项：标记让位给复选框，不画圆点；checked 正确', () => {
+    const d = digest('- [ ] 待办\n- [x] 完成')
+    expect(d.some((x) => x.startsWith('bullet('))).toBe(false)
+    expect(d).toContain('hide("- ")')
+    expect(d.filter((x) => x.startsWith('task('))).toEqual(['task("[ ]")', 'task("[x]")'])
+    const specs = collect('- [x] 完成')
+    expect(specs.find((s) => s.kind === 'task')).toMatchObject({ checked: true })
+  })
+
+  it('围栏：语言标签 + 隐藏闭围栏 + 每行 fenced 类；块内不解析行内语法', () => {
+    const src = '```js\n**not bold**\n```'
+    const d = digest(src)
+    expect(d).toContain('fenceLang("```js")')
+    expect(collect(src).find((s) => s.kind === 'fenceLang')).toMatchObject({ lang: 'js' })
+    expect(d).toContain('line(#1:cm-md-fenced cm-md-fenced-first)')
+    expect(d).toContain('line(#3:cm-md-fenced cm-md-fenced-last)')
+    expect(d.some((x) => x.includes('cm-md-strong'))).toBe(false)
+  })
+
+  it('无语言围栏：起始围栏直接隐藏', () => {
+    const d = digest('```\nx\n```')
+    expect(d.some((x) => x.startsWith('fenceLang('))).toBe(false)
+    expect(d).toContain('hide("```")')
+  })
+
+  it('水平线：整行替换', () => {
+    const d = digest('---')
+    expect(d).toEqual(['hr("---")'])
+  })
+
+  it('表格：每行 cm-md-table，定界符淡化（分隔行两级）', () => {
+    const src = '| a | b |\n| --- | --- |\n| 1 | 2 |'
+    const d = digest(src)
+    expect(d.filter((x) => x.startsWith('line('))).toEqual([
+      'line(#1:cm-md-table)',
+      'line(#2:cm-md-table)',
+      'line(#3:cm-md-table)',
+    ])
+    const specs = collect(src)
+    const delims = specs.filter((s): s is Extract<Spec, { kind: 'tableMark' }> => s.kind === 'tableMark')
+    expect(delims.some((s) => s.delimiter)).toBe(true)
+    expect(delims.filter((s) => s.delimiter)).toHaveLength(1) // 只有分隔行是两级淡化
+    expect(delims).toHaveLength(7) // 4 行共 7 个竖线标记
+  })
+
+  it('中文标点与紧邻标记不误判', () => {
+    const d = digest('他说：「**重点**」。')
+    expect(d).toEqual(['hide("**")', 'mark("重点" cm-md-strong)', 'hide("**")'])
+  })
+
+  it('转义星号不触发强调', () => {
+    const d = digest('\\*不是斜体\\*')
+    expect(d).toEqual([])
+  })
+
+  it('可见区间裁剪：只采集区间内节点', () => {
+    const src = '# 一\n\n# 二'
+    const state = makeState(src)
+    const line3 = state.doc.line(3)
+    const specs = collectSpecs(syntaxTree(state), state.doc, line3.from, line3.to)
+    expect(specs.filter((s) => s.kind === 'line')).toHaveLength(1)
+    expect(specs.find((s) => s.kind === 'line')).toMatchObject({ line: 3 })
+  })
+})
+
+describe('reveal.ts 光标处展开（行粒度）', () => {
+  it('intersectsAny 只认真正的相交', () => {
+    expect(intersectsAny([{ from: 0, to: 5 }], 5, 6)).toBe(true)
+    expect(intersectsAny([{ from: 0, to: 5 }], 6, 8)).toBe(false)
+    expect(intersectsAny([{ from: 0, to: 5 }], 3, 3)).toBe(false)
+  })
+
+  it('光标行上的标记替代物被撤销，样式类保留', () => {
+    const src = 'a **粗** b'
+    const state = makeState(src, 5) // 光标落在粗体所在行
+    const specs = collect(src)
+    const shown = applyReveal(specs, activeLineRanges(state))
+    expect(shown.some((s) => s.kind === 'hide')).toBe(false)
+    expect(shown.some((s) => s.kind === 'mark' && s.cls === 'cm-md-strong')).toBe(true)
+  })
+
+  it('光标在别的行时标记保持隐藏', () => {
+    const src = '第一行\n第二行 **粗**'
+    const state = makeState(src, 0)
+    const specs = collect(src)
+    const shown = applyReveal(specs, activeLineRanges(state))
+    expect(shown.filter((s) => s.kind === 'hide')).toHaveLength(2)
+  })
+
+  it('选区横跨多行时，涉及的行全部展开', () => {
+    const src = '> 一\n> > 二'
+    const state = EditorState.create({
+      doc: src,
+      selection: { anchor: 0, head: src.length },
+      extensions: [markdown({ base: markdownLanguage })],
+    })
+    const shown = applyReveal(collect(src), activeLineRanges(state))
+    expect(shown.filter((s) => s.kind === 'quote')).toHaveLength(0)
+  })
+
+  it('二分优化与线性扫描结果完全一致（含空/重叠/乱序/相邻区间）', () => {
+    const src = '# 标题 **粗** 与 `码` 与 [链](https://a.example)\n\n- 甲\n> 乙\n\n---\n'
+    const specs = collect(src)
+    const cases: { from: number; to: number }[][] = [
+      [],
+      [{ from: 0, to: 2 }],
+      [{ from: 0, to: 2 }, { from: 2, to: 4 }],
+      [{ from: 5, to: 9 }, { from: 0, to: 3 }], // 乱序
+      [{ from: 0, to: 10 }, { from: 4, to: 6 }], // 重叠
+      [{ from: 0, to: src.length }], // 整篇
+      [{ from: 3, to: 3 }], // 零长
+    ]
+    for (const ranges of cases) {
+      const linear = specs.filter((s) => !(s.reveal && intersectsAny(ranges, s.from, s.to)))
+      expect(applyReveal(specs, ranges)).toEqual(linear)
+    }
+  })
+
+  it('selectionEndpointLines 只取选区端点行（Cmd+A 不退化为全文档装饰）', () => {
+    const src = '第 1 行\n第 2 行\n第 3 行\n第 4 行'
+    const state = EditorState.create({
+      doc: src,
+      selection: { anchor: 0, head: src.length },
+      extensions: [markdown({ base: markdownLanguage })],
+    })
+    expect(activeLineRanges(state)).toHaveLength(4)
+    const endpoints = selectionEndpointLines(state)
+    expect(endpoints).toHaveLength(2)
+    expect(endpoints[0].from).toBe(0)
+    expect(endpoints[1].to).toBe(state.doc.line(4).to)
+  })
+})
+
+describe('decorations.ts 构建与安全', () => {
+  const src = '# 标题\n\n- A\n\n![x](/api/images/1)\n'
+
+  it('生成装饰集且原子区间与隐藏区间数量一致', () => {
+    const state = makeState(src)
+    const { decorations, atomic } = buildDecorations(state, [{ from: 0, to: src.length }], true)
+    expect(decorations.size).toBeGreaterThan(0)
+    // hide(1: `# `) + hide(1: `- `) = 2 个原子区间
+    expect(atomic.size).toBe(2)
+  })
+
+  it('光标行上的标记不进入原子区间', () => {
+    const state = makeState(src, 0) // 光标在标题行
+    const { atomic } = buildDecorations(state, [{ from: 0, to: src.length }], true)
+    expect(atomic.size).toBe(2) // 标题标记已展开，只剩列表标记 + 图片替换
+  })
+
+  it('未聚焦（reveal=false）时整篇按渲染态呈现，光标行的标记也隐藏（决策 E11）', () => {
+    const state = makeState(src, 0)
+    const { atomic, decorations } = buildDecorations(state, [{ from: 0, to: src.length }], false)
+    expect(atomic.size).toBe(3) // 标题 + 列表 + 图片全部原子化
+    const hidden: string[] = []
+    decorations.between(0, src.length, (from, to) => {
+      if (to > from) hidden.push(src.slice(from, to))
+    })
+    expect(hidden).toContain('# ')
+  })
+
+  it('图片 src 白名单：站内接口放行，javascript:/外链降级为源码文本', () => {
+    expect(IMAGE_SRC_ALLOW.test('/api/images/12')).toBe(true)
+    expect(IMAGE_SRC_ALLOW.test('data:image/png;base64,AAAA')).toBe(true)
+    expect(IMAGE_SRC_ALLOW.test('javascript:alert(1)')).toBe(false)
+    expect(IMAGE_SRC_ALLOW.test('https://evil.example/x.png')).toBe(false)
+
+    const bad = '![x](javascript:alert(1))'
+    const badState = makeState(bad)
+    const badSet = buildDecorations(badState, [{ from: 0, to: bad.length }], true).decorations
+    expect(badSet.size).toBe(0) // 不产出 <img>，源码原样可见
+
+    const goodState = makeState(src)
+    const goodSet = buildDecorations(goodState, [{ from: 0, to: src.length }], true).decorations
+    const widgets: unknown[] = []
+    goodSet.between(0, src.length, (_from, _to, value) => {
+      widgets.push(value.spec.widget)
+    })
+    expect(widgets.some((w) => w instanceof ImageWidget)).toBe(true)
+  })
+
+  it('widget DOM 走 textContent，语言名里的 HTML 不被解析', () => {
+    const dom = new FenceLangWidget('<img src=x onerror=alert(1)>').toDOM()
+    expect(dom.children).toHaveLength(0)
+    expect(dom.innerHTML).not.toContain('<img')
+    expect(dom.textContent).toBe('<img src=x onerror=alert(1)>')
+  })
+
+  it('图片 widget 不写入 innerHTML，只设置属性', () => {
+    const dom = new ImageWidget('/api/images/1', '"><script>alert(1)</script>').toDOM()
+    expect(dom.querySelector('script')).toBeNull()
+    expect(dom.getAttribute('src')).toBe('/api/images/1')
+    expect(dom.getAttribute('alt')).toBe('"><script>alert(1)</script>')
+  })
+
+  it('任务 widget 挂载时不产生额外 DOM 面', () => {
+    const dom = new TaskWidget(0, 3, false).toDOM({ dispatch() {} } as never) as HTMLInputElement
+    expect(dom.tagName).toBe('INPUT')
+    expect(dom.getAttribute('type')).toBe('checkbox')
+    expect(dom.checked).toBe(false)
+  })
+})