feat: Advanced file editor and file tree improvements (#444)

# Features
- File drag and drop upload: Support uploading files and folders via drag and drop
- Binary file handling: Detect binary files and display a friendly message instead of trying to edit them
- Folder download: Download folders as ZIP files (using JSZip library)
- Context menu integration: Full right-click context menu for file operations (rename, delete, copy path, download, new file/folder)

src/i18n/locales/en/codeEditor.json

@@ -28,5 +28,9 @@
     "lines": "Lines:",
     "characters": "Characters:",
     "shortcuts": "Press Ctrl+S to save • Esc to close"
+  },
+  "binaryFile": {
+    "title": "Binary File",
+    "message": "The file \"{{fileName}}\" cannot be displayed in the text editor because it is a binary file."
   }
 }

src/i18n/locales/en/common.json

@@ -114,7 +114,11 @@
     "justNow": "just now",
     "minAgo": "{{count}} min ago",
     "hoursAgo": "{{count}} hours ago",
-    "daysAgo": "{{count}} days ago"
+    "daysAgo": "{{count}} days ago",
+    "newFile": "New File (Cmd+N)",
+    "newFolder": "New Folder (Cmd+Shift+N)",
+    "refresh": "Refresh",
+    "collapseAll": "Collapse All"
   },
   "projectWizard": {
     "title": "Create New Project",

src/i18n/locales/ja/codeEditor.json

@@ -26,5 +26,9 @@
     "lines": "行数:",
     "characters": "文字数:",
     "shortcuts": "Ctrl+Sで保存 • Escで閉じる"
+  },
+  "binaryFile": {
+    "title": "バイナリファイル",
+    "message": "ファイル \"{{fileName}}\" はバイナリファイルのため、テキストエディタで表示できません。"
   }
 }

src/i18n/locales/ja/common.json

@@ -114,7 +114,11 @@
     "justNow": "たった今",
     "minAgo": "{{count}}分前",
     "hoursAgo": "{{count}}時間前",
-    "daysAgo": "{{count}}日前"
+    "daysAgo": "{{count}}日前",
+    "newFile": "新規ファイル (Cmd+N)",
+    "newFolder": "新規フォルダ (Cmd+Shift+N)",
+    "refresh": "更新",
+    "collapseAll": "すべて折りたたむ"
   },
   "projectWizard": {
     "title": "新規プロジェクトを作成",

src/i18n/locales/ko/codeEditor.json

@@ -26,5 +26,9 @@
     "lines": "줄:",
     "characters": "문자:",
     "shortcuts": "Ctrl+S로 저장 • Esc로 닫기"
+  },
+  "binaryFile": {
+    "title": "바이너리 파일",
+    "message": "파일 \"{{fileName}}\"은(는) 바이너리 파일이므로 텍스트 편집기에서 표시할 수 없습니다."
   }
 }

src/i18n/locales/ko/common.json

@@ -114,7 +114,11 @@
     "justNow": "방금 전",
     "minAgo": "{{count}}분 전",
     "hoursAgo": "{{count}}시간 전",
-    "daysAgo": "{{count}}일 전"
+    "daysAgo": "{{count}}일 전",
+    "newFile": "새 파일 (Cmd+N)",
+    "newFolder": "새 폴더 (Cmd+Shift+N)",
+    "refresh": "새로고침",
+    "collapseAll": "모두 접기"
   },
   "projectWizard": {
     "title": "새 프로젝트 생성",

src/i18n/locales/zh-CN/codeEditor.json

@@ -26,5 +26,9 @@
     "lines": "行数：",
     "characters": "字符数：",
     "shortcuts": "按 Ctrl+S 保存 • Esc 关闭"
+  },
+  "binaryFile": {
+    "title": "二进制文件",
+    "message": "文件 \"{{fileName}}\" 无法在文本编辑器中显示，因为它是二进制文件。"
   }
 }

src/i18n/locales/zh-CN/common.json

@@ -114,7 +114,11 @@
     "justNow": "刚刚",
     "minAgo": "{{count}} 分钟前",
     "hoursAgo": "{{count}} 小时前",
-    "daysAgo": "{{count}} 天前"
+    "daysAgo": "{{count}} 天前",
+    "newFile": "新建文件 (Cmd+N)",
+    "newFolder": "新建文件夹 (Cmd+Shift+N)",
+    "refresh": "刷新",
+    "collapseAll": "全部折叠"
   },
   "projectWizard": {
     "title": "创建新项目",