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/components/code-editor/utils/binaryFile.ts

@@ -0,0 +1,22 @@
+// Binary file extensions (images are handled by ImageViewer, not here)
+const BINARY_EXTENSIONS = [
+  // Archives
+  'zip', 'tar', 'gz', 'rar', '7z', 'bz2', 'xz',
+  // Executables
+  'exe', 'dll', 'so', 'dylib', 'app', 'dmg', 'msi',
+  // Media
+  'mp3', 'mp4', 'wav', 'avi', 'mov', 'mkv', 'flv', 'wmv', 'm4a', 'ogg',
+  // Documents
+  'pdf', 'doc', 'docx', 'xls', 'xlsx', 'ppt', 'pptx', 'odt', 'ods', 'odp',
+  // Fonts
+  'ttf', 'otf', 'woff', 'woff2', 'eot',
+  // Database
+  'db', 'sqlite', 'sqlite3',
+  // Other binary
+  'bin', 'dat', 'iso', 'img', 'class', 'jar', 'war', 'pyc', 'pyo'
+];
+
+export const isBinaryFile = (filename: string): boolean => {
+  const ext = filename.split('.').pop()?.toLowerCase();
+  return BINARY_EXTENSIONS.includes(ext ?? '');
+};