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>

requirements.txt

@@ -0,0 +1,30 @@
+# Real-ESRGAN Web UI Dependencies
+
+# Gradio UI Framework
+gradio>=6.0.0
+gradio-imageslider>=0.0.20
+
+# PyTorch (CUDA 12.1)
+--extra-index-url https://download.pytorch.org/whl/cu121
+torch>=2.0.0
+torchvision>=0.15.0
+
+# Real-ESRGAN and dependencies
+realesrgan>=0.3.0
+basicsr>=1.4.2
+
+# Face Enhancement
+gfpgan>=1.3.8
+facexlib>=0.3.0
+
+# Video Processing
+av>=10.0.0
+
+# Image Processing
+opencv-python>=4.8.0
+Pillow>=10.0.0
+numpy>=1.24.0
+
+# Utilities
+tqdm>=4.65.0
+requests>=2.28.0