Feature/batch converter web UI

.gitignore

@@ -165,3 +165,7 @@ cython_debug/
 src/.DS_Store
 .DS_Store
 .cursorrules
+
+# MarkItDown Batch Converter - User files
+uploads/
+outputs/

BATCH_CONVERTER_README.md

@@ -0,0 +1,130 @@
+# MarkItDown Batch Converter Web Interface
+
+A modern web-based batch converter for MarkItDown with real-time notifications and drag-and-drop functionality.
+
+## 🌟 Features
+
+- **Modern Web UI**: Clean, responsive interface built with TailwindCSS
+- **Drag & Drop**: Intuitive file upload with visual feedback
+- **Batch Processing**: Convert multiple files simultaneously
+- **Real-Time Updates**: Server-Sent Events (SSE) for instant completion notifications
+- **Progress Tracking**: Live progress bars and status indicators
+- **File Management**: Easy queue management with download/delete options
+- **Toast Notifications**: Elegant user feedback system
+- **Dark/Light Theme**: Automatic theme detection
+
+## 🚀 Quick Start
+
+### Prerequisites
+- Python 3.8+
+- Flask
+- MarkItDown library
+
+### Installation
+
+1. Install dependencies:
+```bash
+pip install -r requirements-server.txt
+```
+
+2. Start the server:
+```bash
+python server.py
+```
+
+3. Open your browser to: `http://localhost:5000`
+
+## 🏗️ Architecture
+
+### Backend (Flask)
+- **RESTful API** for file operations
+- **Server-Sent Events** for real-time notifications
+- **Background threading** for non-blocking conversions
+- **Secure file handling** with proper validation
+
+### Frontend (Vanilla JS)
+- **EventSource API** for SSE connection
+- **Responsive design** with TailwindCSS
+- **Real-time UI updates** without polling
+- **Progressive enhancement** approach
+
+## 📡 Real-Time System
+
+Instead of traditional polling, this implementation uses **Server-Sent Events (SSE)**:
+
+```javascript
+// Frontend listens for real-time updates
+eventSource.addEventListener('status_update', function(e) {
+    const data = JSON.parse(e.data);
+    updateFileStatus(data); // Instant UI update
+});
+```
+
+```python
+# Backend sends immediate notifications
+def notify_status_change(file_id, status):
+    broadcast_notification('status_update', {
+        'file_id': file_id,
+        'status': status
+    })
+```
+
+## 🎯 Benefits Over Polling
+
+| Aspect | Polling | SSE (This Implementation) |
+|--------|---------|---------------------------|
+| **Latency** | 200-500ms delay | Instant (0ms) |
+| **Server Load** | High (constant requests) | Low (push-only) |
+| **Bandwidth** | Wasteful | Efficient |
+| **User Experience** | Delayed updates | Real-time feedback |
+
+## 📁 File Structure
+
+```
+├── server.py              # Flask backend with SSE
+├── code.html             # Web interface
+├── requirements-server.txt # Python dependencies
+├── start_converter.bat   # Windows startup script
+├── uploads/              # Temporary file storage
+└── outputs/              # Converted markdown files
+```
+
+## 🔧 API Endpoints
+
+- `GET /` - Serve web interface
+- `POST /api/upload` - Upload files
+- `POST /api/convert` - Start batch conversion
+- `GET /api/status` - Get current job status
+- `GET /api/events` - SSE endpoint for real-time updates
+- `GET /api/download/<id>` - Download converted file
+- `DELETE /api/delete/<id>` - Remove file from queue
+
+## 🎨 UI Components
+
+- **File Drop Zone**: Visual drag-and-drop area
+- **Conversion Queue**: Real-time file status list
+- **Progress Bar**: Overall conversion progress
+- **Toast Notifications**: Success/error messages
+- **Live Indicator**: Connection status display
+
+## 🔒 Security Features
+
+- **Secure filename handling** with werkzeug
+- **File size limits** (100MB max)
+- **Input validation** on all endpoints
+- **Error handling** with proper HTTP status codes
+
+## 🚀 Performance Optimizations
+
+- **Background threading** for non-blocking conversions
+- **SSE connection pooling** for multiple clients
+- **Efficient file handling** with streaming
+- **Auto-cleanup** of temporary files
+
+## 🤝 Contributing
+
+This batch converter extends MarkItDown's capabilities while maintaining compatibility with the core library. It adds a user-friendly web interface without modifying the original conversion logic.
+
+## 📄 License
+
+Follows the same license as the main MarkItDown project.