feat: v2.0 — 插件改造，集成 PPTX 导出

改造内容：
- 改名 Web to Pixso → Web to PPT
- 删除 pixso-plugin/、element-picker.js、popup-panel.js
- 新增 convert-browser.js（浏览器版转化逻辑）
- 新增 lib-pptxgen.js（pptxgenjs 浏览器 bundle）
- 重写 popup.js（触发捕获→转化→下载）
- 重写 background.js（缓存采集数据，支持 WEB_TO_PPT_GET_DATA）
- manifest.json 改名 + 添加 default_popup

流程：popup 点击导出 → background 抓取 DOM → popup 运行转化 → chrome.downloads 下载 PPTX

web-to-pixso/background.js

@@ -1,7 +1,5 @@
 const CAPTURE_FILE = "capture.js";
 const RUNNER_FILE = "runner.js";
-const POPUP_PANEL_FILE = "popup-panel.js";
-const ELEMENT_PICKER_FILE = "element-picker.js";
 const SETTINGS_KEY = "webToPixsoSettings";
 const DEFAULT_SETTINGS = {
   useProxy: false,
@@ -12,6 +10,9 @@ const DEFAULT_SETTINGS = {
 const MIN_CAPTURE_WIDTH = 320;
 const MAX_CAPTURE_WIDTH = 3840;
 
+// 缓存最近一次采集数据，供 popup 获取
+let lastCaptureData = null;
+
 const delay = ms => new Promise(resolve => setTimeout(resolve, ms));
 
 function normalizeSettings(value = {}) {
@@ -43,7 +44,6 @@ function assertCaptureableTab(tab) {
   if (!tab?.id || !tab.url) {
     throw new Error("没有可采集的当前标签页");
   }
-
   if (/^(chrome|edge|about|devtools|chrome-extension):/i.test(tab.url)) {
     throw new Error("浏览器内置页面不支持采集，请切换到普通网页");
   }
@@ -60,22 +60,18 @@ async function runCapture(tabId, options) {
     target: { tabId },
     files: [CAPTURE_FILE]
   });
-
   await chrome.scripting.executeScript({
     target: { tabId },
     files: [RUNNER_FILE]
   });
-
   const [{ result }] = await chrome.scripting.executeScript({
     target: { tabId },
     func: captureOptions => window.__webToPixsoRunCapture(captureOptions),
     args: [options]
   });
-
   if (!result) {
     throw new Error("页面没有返回采集结果");
   }
-
   return result;
 }
 
@@ -133,9 +129,7 @@ async function prepareCaptureViewport(tab, requestedWidth) {
         await chrome.windows.update(tab.windowId, { state: originalState });
       }
       await delay(250);
-    } catch {
-      // Restoring the user's window is best effort only.
-    }
+    } catch {}
   };
 
   try {
@@ -157,7 +151,7 @@ async function prepareCaptureViewport(tab, requestedWidth) {
     }
 
     if (Math.abs(currentViewportWidth - targetWidth) > 2) {
-      throw new Error(`采集视口未生效：目标 ${targetWidth}px，实际 ${currentViewportWidth}px。请退出全屏或手动放宽浏览器窗口后重试。`);
+      throw new Error(`采集视口未生效：目标 ${targetWidth}px，实际 ${currentViewportWidth}px`);
     }
 
     return {
@@ -203,7 +197,7 @@ async function downloadCapture(data) {
     .replace(/[\\/:*?"<>|]+/g, "-")
     .replace(/\s+/g, "-")
     .slice(0, 64) || "webpage";
-  const filename = `web-to-pixso/${safeTitle}-${Date.now()}.json`;
+  const filename = `web-to-ppt/${safeTitle}-${Date.now()}.json`;
 
   await chrome.downloads.download({
     url,
@@ -214,206 +208,67 @@ async function downloadCapture(data) {
   return filename;
 }
 
-async function startCapture(options) {
-  const settings = normalizeSettings(options);
-  await chrome.storage.local.set({ [SETTINGS_KEY]: settings });
-  const tab = await getActiveTab();
-  const data = await captureCurrentTab(tab, settings);
-  const filename = await downloadCapture(data);
-  return {
-    ok: true,
-    filename,
-    actualViewportWidth: data.source?.actualViewportWidth,
-    requestedViewportWidth: data.source?.requestedViewportWidth,
-    usedTemporaryWindow: Boolean(data.capture?.usedTemporaryWindow)
-  };
-}
-
-async function startCaptureFromSender(options, sender) {
-  const settings = normalizeSettings(options);
-  await chrome.storage.local.set({ [SETTINGS_KEY]: settings });
-  const tab = sender?.tab || await getActiveTab();
-  assertCaptureableTab(tab);
-  const data = await captureCurrentTab(tab, settings);
-  const filename = await downloadCapture(data);
-  return {
-    ok: true,
-    filename,
-    actualViewportWidth: data.source?.actualViewportWidth,
-    requestedViewportWidth: data.source?.requestedViewportWidth,
-    usedTemporaryWindow: Boolean(data.capture?.usedTemporaryWindow)
-  };
-}
-
-async function captureClipboardFromSender(options, sender) {
-  const settings = normalizeSettings(options);
-  await chrome.storage.local.set({ [SETTINGS_KEY]: settings });
-  const tab = sender?.tab || await getActiveTab();
-  assertCaptureableTab(tab);
-  const data = await captureCurrentTab(tab, settings);
-  return {
-    ok: true,
-    json: JSON.stringify(data, null, 2),
-    actualViewportWidth: data.source?.actualViewportWidth,
-    requestedViewportWidth: data.source?.requestedViewportWidth,
-    usedTemporaryWindow: Boolean(data.capture?.usedTemporaryWindow)
-  };
-}
-
-async function startElementCapture(options, sender) {
-  const settings = {
-    ...normalizeSettings(options),
-    captureWidth: null,
-    selectionId: options?.selectionId,
-    selectionWidth: Math.max(1, Math.round(Number(options?.selectionWidth || 0))),
-    captureMode: "mixed"
-  };
-  const tab = sender?.tab || await getActiveTab();
-  assertCaptureableTab(tab);
-  const data = await runCapture(tab.id, settings);
-  const filename = await downloadCapture(data);
-  return {
-    ok: true,
-    filename,
-    actualViewportWidth: data.source?.actualViewportWidth,
-    requestedViewportWidth: data.source?.requestedViewportWidth,
-    selectionWidth: data.import?.defaultWidth
-  };
-}
-
-async function fetchWithTimeout(url, timeout = 10000) {
-  const controller = new AbortController();
-  const timeoutId = setTimeout(() => controller.abort(), timeout);
-
-  try {
-    return await fetch(url, {
-      signal: controller.signal,
-      credentials: "include",
-      cache: "force-cache"
-    });
-  } finally {
-    clearTimeout(timeoutId);
-  }
-}
-
 function arrayBufferToBase64(buffer) {
   const bytes = new Uint8Array(buffer);
   const chunkSize = 0x8000;
   let binary = "";
-
   for (let index = 0; index < bytes.length; index += chunkSize) {
     binary += String.fromCharCode(...bytes.subarray(index, index + chunkSize));
   }
-
   return btoa(binary);
 }
 
-async function proxyFetchAsset(url) {
-  if (!/^https?:\/\//i.test(url)) {
-    return { ok: false, error: "仅支持 http/https 图片代理" };
+// 消息处理
+chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
+  // 采集并下载 JSON（兼容旧流程）
+  if (message?.type === "PIXSO_CAPTURE_START") {
+    (async () => {
+      const settings = normalizeSettings(message.options);
+      await chrome.storage.local.set({ [SETTINGS_KEY]: settings });
+      const tab = sender?.tab || await getActiveTab();
+      assertCaptureableTab(tab);
+      const data = await captureCurrentTab(tab, settings);
+      lastCaptureData = data; // 缓存数据
+      const filename = await downloadCapture(data);
+      return {
+        ok: true,
+        filename,
+        actualViewportWidth: data.source?.actualViewportWidth,
+        requestedViewportWidth: data.source?.requestedViewportWidth
+      };
+    })()
+      .then(sendResponse)
+      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
+    return true;
   }
 
-  const response = await fetchWithTimeout(url, 12000);
-  if (!response.ok) {
-    return { ok: false, status: response.status, error: `HTTP ${response.status}` };
+  // 获取最近一次采集数据（供 popup 转化用）
+  if (message?.type === "WEB_TO_PPT_GET_DATA") {
+    if (lastCaptureData) {
+      sendResponse({ ok: true, data: lastCaptureData });
+    } else {
+      // 如果没有缓存，重新采集
+      (async () => {
+        const settings = normalizeSettings({});
+        const tab = await getActiveTab();
+        const data = await captureCurrentTab(tab, settings);
+        lastCaptureData = data;
+        return { ok: true, data };
+      })()
+        .then(sendResponse)
+        .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
+    }
+    return true;
   }
 
-  const contentType = response.headers.get("content-type") || "application/octet-stream";
-  const buffer = await response.arrayBuffer();
-
-  return {
-    ok: true,
-    status: response.status,
-    contentType,
-    base64: arrayBufferToBase64(buffer)
-  };
-}
-
-async function captureVisibleTab(sender) {
-  if (!sender?.tab?.windowId || !chrome.tabs?.captureVisibleTab) {
-    return { ok: false, error: "当前标签页截图不可用" };
-  }
-
-  try {
-    const dataUrl = await chrome.tabs.captureVisibleTab(sender.tab.windowId, {
-      format: "png"
-    });
-    return { ok: true, dataUrl };
-  } catch (error) {
-    return {
-      ok: false,
-      error: error.message || String(error),
-      nonFatal: true
-    };
-  }
-}
-
-async function showInPagePanel(tab) {
-  assertCaptureableTab(tab);
-  await chrome.scripting.executeScript({
-    target: { tabId: tab.id },
-    files: [ELEMENT_PICKER_FILE, POPUP_PANEL_FILE]
-  });
-  await chrome.scripting.executeScript({
-    target: { tabId: tab.id },
-    func: () => window.__webToPixsoShowPanel?.()
-  });
-}
+  return false;
+});
 
+// 安装时初始化设置
 chrome.runtime.onInstalled.addListener(() => {
   chrome.storage.local.get({ [SETTINGS_KEY]: DEFAULT_SETTINGS }).then(result => {
     chrome.storage.local.set({ [SETTINGS_KEY]: normalizeSettings(result[SETTINGS_KEY]) });
   });
 });
 
-chrome.action.onClicked.addListener(tab => {
-  showInPagePanel(tab).catch(error => {
-    console.warn("[Web to Pixso] Failed to open panel", error);
-  });
-});
-
-chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
-  if (message?.type === "PIXSO_CAPTURE_START") {
-    startCapture(message.options)
-      .then(sendResponse)
-      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
-    return true;
-  }
-
-  if (message?.type === "PIXSO_CAPTURE_ELEMENT_START") {
-    startElementCapture(message.options, sender)
-      .then(sendResponse)
-      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
-    return true;
-  }
-
-  if (message?.type === "PIXSO_CAPTURE_CURRENT_TAB") {
-    startCaptureFromSender(message.options, sender)
-      .then(sendResponse)
-      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
-    return true;
-  }
-
-  if (message?.type === "PIXSO_CAPTURE_CLIPBOARD") {
-    captureClipboardFromSender(message.options, sender)
-      .then(sendResponse)
-      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
-    return true;
-  }
-
-  if (message?.type === "PIXSO_CAPTURE_FETCH_ASSET") {
-    proxyFetchAsset(message.url)
-      .then(sendResponse)
-      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
-    return true;
-  }
-
-  if (message?.type === "PIXSO_CAPTURE_VISIBLE_TAB") {
-    captureVisibleTab(sender)
-      .then(sendResponse)
-      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
-    return true;
-  }
-
-  return false;
-});
+// 点击图标打开 popup（MV3 默认行为）