fix: dynamic timeout for Puppeteer PDF generation

Replace fixed timeouts with dynamic calculation based on image count
and total image size to prevent TimeoutError on large PDF exports

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server.js

@@ -74,6 +74,28 @@ app.post('/api/generate_pdf', async (req, res) => {
     const sizeWaitTime = imgSizeMB > 0 ? Math.min(imgSizeMB * 100, 3000) : 0;
     const totalWaitTime = Math.min(baseWaitTime + sizeWaitTime, 8000);
 
+    // 动态计算 waitForNetworkIdle 超时上限
+    const baseTimeout = 30000;
+    let extraMs = 0;
+    if (imgCount <= 30) {
+      extraMs = imgCount * 3000;
+    } else if (imgCount <= 50) {
+      extraMs = 90000 + (imgCount - 30) * 10000;
+    } else if (imgCount <= 100) {
+      extraMs = 290000 + (imgCount - 50) * 7000;
+    } else {
+      extraMs = 640000 + (imgCount - 100) * 5600;
+    }
+    const sizeExtraMs = (imgSizeMB || 0) * 3000;
+    const networkTimeout = Math.min(baseTimeout + extraMs + sizeExtraMs, 1200000);
+
+    // 动态计算 setContent 超时上限（setContent 需要解析 HTML + 加载资源）
+    const setContentTimeout = Math.min(60000 + extraMs + sizeExtraMs, 600000);
+
+    // 动态计算截图超时上限
+    const screenshotTimeout = Math.min(30000 + (imgCount > 0 ? extraMs / 10 : 0), 120000);
+
+    console.log(`[PDF-GEN] [${getElapsed()}] 动态超时: setContent=${(setContentTimeout / 1000).toFixed(0)}s, waitForNetworkIdle=${(networkTimeout / 1000).toFixed(0)}s`);
     console.log(`[PDF-GEN] [${getElapsed()}] 正在启动浏览器...`);
     browser = await puppeteer.launch({
       executablePath: '/usr/bin/chromium',
@@ -91,14 +113,16 @@ app.post('/api/generate_pdf', async (req, res) => {
     console.log(`[PDF-GEN] [${getElapsed()}] 浏览器启动成功`);
 
     const page = await browser.newPage();
+    // 设置 viewport 满足大部分页面渲染需求
     await page.setViewport({ width: 1200, height: 800 });
+    console.log(`[PDF-GEN] [${getElapsed()}] Viewport: 1200x800`);
     
     console.log(`[PDF-GEN] [${getElapsed()}] 正在填充页面内容...`);
-    await page.setContent(htmlToUse, { 
+    await page.setContent(htmlToUse, {
       waitUntil: ['load', 'networkidle0'],
-      timeout: 120000
+      timeout: setContentTimeout
     });
-    await page.waitForNetworkIdle({ idleTime: 500 });
+    await page.waitForNetworkIdle({ idleTime: 500, timeout: networkTimeout });
     console.log(`[PDF-GEN] [${getElapsed()}] 页面内容加载完成`);
     
     // 等待 base64 图片完全渲染（检测实际加载状态）
@@ -158,7 +182,7 @@ app.post('/api/generate_pdf', async (req, res) => {
           });
         }
         
-        return { 
+        return {
           initial: results,
           final: finalResults,
           total: images.length
@@ -208,7 +232,7 @@ app.post('/api/generate_pdf', async (req, res) => {
       
       // 根据 GitHub Issue #10341：截图可以强制触发渲染流水线
       console.log(`[PDF-GEN] [${getElapsed()}] 截图强制渲染（Issue #10341 workaround）...`);
-      await page.screenshot({ type: 'png' });
+      await page.screenshot({ type: 'png', timeout: screenshotTimeout });
       console.log(`[PDF-GEN] [${getElapsed()}] 截图完成`);
     } else {
       console.log(`[PDF-GEN] [${getElapsed()}] 无图片，等待 DOM 稳定...`);
@@ -216,6 +240,7 @@ app.post('/api/generate_pdf', async (req, res) => {
     }
 
     console.log(`[PDF-GEN] [${getElapsed()}] 正在生成 PDF 二进制流...`);
+    
     const pdfBuffer = await page.pdf({
       format: 'A4',
       printBackground: true,