feat(upload): 实现Canvas转换法,彻底解决远端服务器图片上传限制

frontend/index.html

@@ -1180,7 +1180,7 @@
     </div>
 
     <!-- Scripts -->
-    <script src="/static/js/main.js?v=5.0"></script>
+    <script src="/static/js/main.js?v=5.1"></script>
     <script src="/static/js/trial-periods.js?v=1.3"></script>
     <script src="/static/js/trial-periods-page.js?v=1.6"></script>
 </body>

frontend/js/main.js

@@ -61,7 +61,7 @@ function canDelete() {
 }
 
 document.addEventListener("DOMContentLoaded", function () {
-  console.log("CRM System Main JS v5.0 Loaded - " + new Date().toLocaleString());
+  console.log("CRM System Main JS v5.1 Loaded - " + new Date().toLocaleString());
   // 登录守卫
   const token = localStorage.getItem("crmToken");
   if (!token && !window.location.pathname.endsWith("login.html")) {
@@ -3235,25 +3235,42 @@ document.addEventListener("DOMContentLoaded", function () {
 
       const newBase64Images = [];
 
-      // Helper to convert file to base64 with retry
-      const fileToBase64 = async (f, attempt = 1) => {
+      // Canvas-based conversion - most compatible method for restricted environments
+      const fileToBase64Canvas = (file) => {
+        return new Promise((resolve, reject) => {
+          // Create object URL from file
+          const url = URL.createObjectURL(file);
+          const img = new Image();
+
+          img.onload = () => {
             try {
-          return await new Promise((resolve, reject) => {
-            const reader = new FileReader();
-            reader.onload = () => resolve(reader.result);
-            reader.onerror = () => reject(reader.error || new Error("FileReader error"));
-            reader.onabort = () => reject(new Error("File read aborted"));
-            reader.readAsDataURL(f);
+              // Create canvas and draw image
+              const canvas = document.createElement('canvas');
+              canvas.width = img.width;
+              canvas.height = img.height;
+
+              const ctx = canvas.getContext('2d');
+              ctx.drawImage(img, 0, 0);
+
+              // Convert to base64
+              const base64 = canvas.toDataURL(file.type || 'image/png');
+
+              // Clean up
+              URL.revokeObjectURL(url);
+              resolve(base64);
+            } catch (error) {
+              URL.revokeObjectURL(url);
+              reject(error);
+            }
+          };
+
+          img.onerror = () => {
+            URL.revokeObjectURL(url);
+            reject(new Error('Failed to load image'));
+          };
+
+          img.src = url;
         });
-        } catch (err) {
-          // If NotReadableError, retry up to 3 times
-          if (attempt < 3 && (err.name === "NotReadableError" || err.code === 1)) {
-            console.warn(`Retrying ${f.name} read due to error (attempt ${attempt})...`);
-            await new Promise(r => setTimeout(r, 200 * attempt));
-            return fileToBase64(f, attempt + 1);
-          }
-          throw err;
-        }
       };
 
       for (const file of files) {
@@ -3263,31 +3280,13 @@ document.addEventListener("DOMContentLoaded", function () {
         }
 
         try {
-          console.log(`[v5.0] Converting ${file.name} (${file.size} bytes)...`);
-          const base64 = await fileToBase64(file);
+          console.log(`[v5.1-Canvas] Converting ${file.name} (${file.size} bytes)...`);
+          const base64 = await fileToBase64Canvas(file);
           newBase64Images.push(base64);
-          console.log(`Successfully converted ${file.name}`);
+          console.log(`✅ Successfully converted ${file.name} using Canvas method`);
         } catch (error) {
-          console.error(`Primary method failed for ${file.name}:`, error);
-
-          // Fallback: arrayBuffer (usually works when FileReader fails)
-          try {
-            console.log(`Trying arrayBuffer fallback for ${file.name}...`);
-            const buffer = await file.arrayBuffer();
-            const bytes = new Uint8Array(buffer);
-            let binary = "";
-            const chunkSize = 8192;
-            for (let i = 0; i < bytes.length; i += chunkSize) {
-              const chunk = bytes.slice(i, i + chunkSize);
-              binary += String.fromCharCode.apply(null, chunk);
-            }
-            const b64 = `data:${file.type};base64,${btoa(binary)}`;
-            newBase64Images.push(b64);
-            console.log(`Fallback successful for ${file.name}`);
-          } catch (fallbackError) {
-            console.error(`Both methods failed for ${file.name}:`, fallbackError);
-            alert(`无法读取文件 "${file.name}"。\n这种情况通常是浏览器或系统文件锁定导致的。\n\n建议尝试：\n1. 刷新页面后再试\n2. 使用浏览器的“无痕模式”\n3. 确认文件没有被其他软件打开`);
-          }
+          console.error(`❌ Canvas method failed for ${file.name}:`, error);
+          alert(`无法处理文件 "${file.name}"。\n\n可能的原因：\n1. 图片格式不受支持\n2. 图片文件损坏\n3. 浏览器内存不足\n\n建议：\n• 尝试使用较小的图片\n• 转换为标准格式（JPG/PNG）\n• 刷新页面后重试`);
         }
       }