feat: initial implementation of Real-ESRGAN Web UI

Full-featured Gradio 6.0+ web interface for Real-ESRGAN image/video
upscaling, optimized for RTX 4090 (24GB VRAM).

Features:
- Image upscaling with before/after comparison (ImageSlider)
- Video upscaling with progress tracking and checkpoint/resume
- Face enhancement via GFPGAN integration
- Multiple codecs: H.264, H.265, AV1 (with NVENC support)
- Batch processing queue with SQLite persistence
- Processing history gallery
- Custom dark theme
- Auto-download of model weights

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

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

app.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+"""
+Real-ESRGAN Web UI - Main Entry Point
+
+A full-featured web interface for Real-ESRGAN image and video upscaling,
+optimized for RTX 4090 with 24GB VRAM.
+
+Usage:
+    python app.py
+
+The server will start at http://localhost:7860
+"""
+
+import sys
+from pathlib import Path
+
+# Add src to path
+sys.path.insert(0, str(Path(__file__).parent))
+
+from src.ui.app import launch_app
+
+
+def main():
+    """Main entry point."""
+    launch_app()
+
+
+if __name__ == "__main__":
+    main()