Fix file upload limits and UI performance issues

- Remove artificial 18MB file size restrictions across all layers
- Increase limits to industry standard: 5GB for file operations, 1GB for JSON
- Eliminate duplicate resize handlers causing UI instability
- Fix Terminal connection blank screen by removing 300ms delay
- Optimize clipboard state flow for copy/paste functionality
- Complete i18n implementation removing hardcoded strings
- Apply Linus principle: eliminate complexity, fix data structure issues

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/ui/Desktop/Apps/File Manager/components/DiffViewer.tsx

@@ -139,11 +139,11 @@ export function DiffViewer({
         document.body.removeChild(link);
         URL.revokeObjectURL(url);
 
-        toast.success(`文件下载成功: ${file.name}`);
+        toast.success(t("fileManager.downloadFileSuccess", { name: file.name }));
       }
     } catch (error: any) {
       console.error("Failed to download file:", error);
-      toast.error(`下载失败: ${error.message || "未知错误"}`);
+      toast.error(t("fileManager.downloadFileFailed") + ": " + (error.message || t("fileManager.unknownError")));
     }
   };
 

src/ui/Desktop/Apps/File Manager/components/DraggableWindow.tsx

@@ -221,7 +221,7 @@ export function DraggableWindow({
                 e.stopPropagation();
                 onMinimize();
               }}
-              title="最小化"
+              title={t("common.minimize")}
             >
               <Minus className="w-4 h-4" />
             </button>
@@ -250,7 +250,7 @@ export function DraggableWindow({
               e.stopPropagation();
               onClose();
             }}
-            title="关闭"
+            title={t("common.close")}
           >
             <X className="w-4 h-4" />
           </button>

src/ui/Desktop/Apps/File Manager/components/FileViewer.tsx

@@ -294,9 +294,9 @@ export function FileViewer({
 
   const fileTypeInfo = getFileType(file.name);
 
-  // 文件大小限制 (1MB for warning, 10MB for hard limit)
-  const WARNING_SIZE = 1024 * 1024; // 1MB
-  const MAX_SIZE = 10 * 1024 * 1024; // 10MB
+  // 文件大小限制 - 移除硬限制，支持大文件处理
+  const WARNING_SIZE = 50 * 1024 * 1024; // 50MB 警告
+  const MAX_SIZE = Number.MAX_SAFE_INTEGER; // 移除硬限制
 
   // 检查是否应该显示为文本
   const shouldShowAsText =
@@ -580,7 +580,7 @@ export function FileViewer({
         <div className="flex-shrink-0 bg-muted/30 border-b border-border p-3">
           <div className="flex items-center gap-2 mb-2">
             <Input
-              placeholder="Find..."
+              placeholder={t("fileManager.find")}
               value={searchText}
               onChange={(e) => {
                 setSearchText(e.target.value);
@@ -629,7 +629,7 @@ export function FileViewer({
           {showReplacePanel && (
             <div className="flex items-center gap-2 mb-2">
               <Input
-                placeholder="Replace with..."
+                placeholder={t("fileManager.replaceWith")}
                 value={replaceText}
                 onChange={(e) => setReplaceText(e.target.value)}
                 className="w-48 h-8"
@@ -805,7 +805,7 @@ export function FileViewer({
                         value={editedContent}
                         onChange={(e) => handleContentChange(e.target.value)}
                         className="w-full h-full p-4 border-none resize-none outline-none font-mono text-sm overflow-auto bg-background text-foreground"
-                        placeholder="Start typing..."
+                        placeholder={t("fileManager.startTyping")}
                         spellCheck={false}
                       />
                     )}

src/ui/Desktop/Apps/File Manager/components/FileWindow.tsx

@@ -223,7 +223,7 @@ export function FileWindow({
         autoSaveTimerRef.current = null;
       }
 
-      toast.success("File saved successfully");
+      toast.success(t("fileManager.fileSavedSuccessfully"));
     } catch (error: any) {
       console.error("Failed to save file:", error);
 
@@ -236,7 +236,7 @@ export function FileWindow({
           `SSH connection failed. Please check your connection to ${sshHost.name} (${sshHost.ip}:${sshHost.port})`,
         );
       } else {
-        toast.error(`Failed to save file: ${error.message || "Unknown error"}`);
+        toast.error(`${t("fileManager.failedToSaveFile")}: ${error.message || t("fileManager.unknownError")}`);
       }
     } finally {
       setIsLoading(false);
@@ -257,10 +257,10 @@ export function FileWindow({
       try {
         console.log("Auto-saving file...");
         await handleSave(newContent);
-        toast.success("File auto-saved");
+        toast.success(t("fileManager.fileAutoSaved"));
       } catch (error) {
         console.error("Auto-save failed:", error);
-        toast.error("Auto-save failed");
+        toast.error(t("fileManager.autoSaveFailed"));
       }
     }, 60000); // 1分钟 = 60000毫秒
   };
@@ -303,7 +303,7 @@ export function FileWindow({
         document.body.removeChild(link);
         URL.revokeObjectURL(url);
 
-        toast.success("File downloaded successfully");
+        toast.success(t("fileManager.fileDownloadedSuccessfully"));
       }
     } catch (error: any) {
       console.error("Failed to download file:", error);