fix(export): 内联 PDF 字体并清理历史记录

frontend/src/services/pdfSnapshotService.spec.ts

@@ -8,10 +8,17 @@ vi.mock('@/stores/markdownPreferences',()=>({useMarkdownPreferencesStore:()=>({n
 vi.mock('@/stores/headingAppearance',()=>({useHeadingAppearanceStore:()=>({cssVariables:{'--heading-1-size':'37px'},preferences:{custom:true}})}))
 vi.mock('@/components/common/MarkdownContent.vue',()=>({default:{}}))
 vi.mock('@/features/editor/VisualMarkdownEditor.vue',()=>({default:{__scopeId:'data-v-editor'}}))
-import {preparePdfSnapshot} from './pdfSnapshotService'
+import {preparePdfSnapshot,preferWoff2FontSource} from './pdfSnapshotService'
 import {apiClient} from './apiClient'
 import {renderMarkdown} from '@/utils/markdown'
 afterEach(()=>vi.clearAllMocks())
+it('keeps only the WOFF2 source when preparing embedded print fonts',()=>{
+ const css='@font-face { font-family: "Demo"; src: url("data:font/woff2;base64,d09GMg==") format("woff2"), url("demo.woff") format("woff"), url("demo.ttf") format("truetype"); font-style: normal; }'
+ const compact=preferWoff2FontSource(css)
+ expect(compact).toContain('url("data:font/woff2;base64,d09GMg==") format("woff2")')
+ expect(compact).not.toContain('demo.woff"')
+ expect(compact).not.toContain('demo.ttf')
+})
 it('preserves actual theme CSS, pseudo elements, root attributes and heading preferences',async()=>{
  const style=document.createElement('style');style.textContent='[data-theme="paper"] .ProseMirror::before { content:"tape"; transform:rotate(-3deg) }';document.head.append(style)
  document.documentElement.dataset.theme='paper'

frontend/src/services/pdfSnapshotService.ts

@@ -38,8 +38,31 @@ async function dataUrl(url: string, signal?:AbortSignal):Promise<string> {
   const blob=await response.blob()
   return await new Promise((resolve,reject)=>{const reader=new FileReader();reader.onload=()=>resolve(String(reader.result));reader.onerror=reject;reader.readAsDataURL(blob)})
 }
+export function preferWoff2FontSource(css:string):string {
+  if(!/^\s*@font-face\b/i.test(css))return css
+  const declaration=/\bsrc\s*:/i.exec(css)
+  if(!declaration)return css
+  const valueStart=declaration.index+declaration[0].length
+  let quote='',depth=0,valueEnd=-1
+  for(let index=valueStart;index<css.length;index+=1) {
+    const character=css[index]!
+    if(quote) {
+      if(character==='\\')index+=1
+      else if(character===quote)quote=''
+    } else if(character==='"'||character==="'")quote=character
+    else if(character==='(')depth+=1
+    else if(character===')')depth=Math.max(0,depth-1)
+    else if(character===';'&&depth===0){valueEnd=index;break}
+  }
+  if(valueEnd<0)return css
+  const sources=css.slice(valueStart,valueEnd)
+  const woff2=sources.match(/url\(\s*(?:["'][^"']*["']|[^)]*)\s*\)\s*format\(\s*["']?woff2["']?\s*\)/i)
+  return woff2 ? `${css.slice(0,valueStart)} ${woff2[0]}${css.slice(valueEnd)}` : css
+}
 async function embedCss(css: string, base: string, signal?:AbortSignal) {
   // 打印进程完全离线，主题资源必须来自应用同源地址并在此转换为 data URL。
+  // Chromium 支持 WOFF2；丢弃同一字体的 WOFF/TTF 回退，避免重复嵌入三份字体。
+  css=preferWoff2FontSource(css)
   const matches=[...css.matchAll(/url\(\s*(['"]?)(.*?)\1\s*\)/g)]
   for(const match of matches) {
     const url=match[2]!