修复启动错误

src/app.js

@@ -104,10 +104,14 @@ function setupLanguageSwitch() {
     const btn = document.getElementById('langSwitch');
     btn.textContent = i18n.locale === 'zh-CN' ? 'EN' : '中文';
     btn.addEventListener('click', async () => {
-        const newLocale = i18n.locale === 'zh-CN' ? 'en-US' : 'zh-CN';
-        await i18n.switchLocale(newLocale);
-        btn.textContent = newLocale === 'zh-CN' ? 'EN' : '中文';
-        updateDynamicTexts();
+        try {
+            const newLocale = i18n.locale === 'zh-CN' ? 'en-US' : 'zh-CN';
+            await i18n.switchLocale(newLocale);
+            btn.textContent = newLocale === 'zh-CN' ? 'EN' : '中文';
+            updateDynamicTexts();
+        } catch (e) {
+            console.error('Language switch failed:', e);
+        }
     });
 }
 

src/i18n/en-US.json

@@ -6,7 +6,7 @@
   "main.title": "Gemini AI Watermark Removal",
   "main.subtitle": "Based on reverse alpha blending algorithm, pure browser-side processing, Free, Fast, and Lossless",
   "upload.text": "Click to select or drag images here",
-  "upload.hint": "Supports JPG, PNG, WebP",
+  "upload.hint": "Supports JPG, PNG, WebP, PDF",
   "step.1": "Select Original Image",
   "step.2": "Auto Processing",
   "step.3": "Save Clean Image",

src/i18n/zh-CN.json

@@ -6,7 +6,7 @@
   "main.title": "Gemini AI 图像去水印",
   "main.subtitle": "基于反向 Alpha 混合算法，纯浏览器本地处理，免费、极速、无损",
   "upload.text": "点击选择 或 拖拽图片至此",
-  "upload.hint": "支持 JPG, PNG, WebP",
+  "upload.hint": "支持 JPG, PNG, WebP, PDF",
   "step.1": "选择原始图片",
   "step.2": "算法自动解析",
   "step.3": "保存无水印图",