Add automated Real-ESRGAN setup script for Linux

Created setup-realesrgan-linux.sh for easy one-command installation:
- Downloads Real-ESRGAN ncnn Vulkan binary from GitHub releases
- Installs to ~/.local/bin/realesrgan-ncnn-vulkan
- Installs all AI models to ~/.local/share/realesrgan/models/
- Sets proper permissions
- Provides PATH setup instructions

Installation:
  ./scripts/setup-realesrgan-linux.sh

Models included (45MB):
- realesr-animevideov3 (x2, x3, x4) - Anime/illustration upscaling
- realesrgan-x4plus - General photo/video upscaling
- realesrgan-x4plus-anime - Anime-specific upscaling

Tested and working on Fedora 43. Makes AI upscaling fully automated
for Linux users - no manual downloads or configuration needed.

Next step: Add in-app "Install AI Upscaling" button to VideoTools UI
for even easier setup without using terminal.

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

scripts/setup-realesrgan-linux.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+# Quick Real-ESRGAN setup for Linux
+set -e
+
+INSTALL_DIR="$HOME/.local/bin"
+MODELS_DIR="$HOME/.local/share/realesrgan/models"
+
+mkdir -p "$INSTALL_DIR"
+mkdir -p "$MODELS_DIR"
+
+echo "════════════════════════════════════════════════════════════════"
+echo "  Real-ESRGAN ncnn Setup for Linux"
+echo "════════════════════════════════════════════════════════════════"
+echo ""
+
+cd /tmp
+
+echo "📥 Downloading Real-ESRGAN ncnn Vulkan..."
+if ! wget -q --show-progress -O realesrgan-ncnn-vulkan.zip \
+  https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.5.0/realesrgan-ncnn-vulkan-20220424-ubuntu.zip; then
+    echo "❌ Download failed. Please check your internet connection."
+    exit 1
+fi
+
+echo ""
+echo "📦 Extracting..."
+unzip -o realesrgan-ncnn-vulkan.zip > /dev/null
+
+echo "📂 Installing to $INSTALL_DIR..."
+cp realesrgan-ncnn-vulkan "$INSTALL_DIR/"
+chmod +x "$INSTALL_DIR/realesrgan-ncnn-vulkan"
+
+echo "📂 Installing models to $MODELS_DIR..."
+cp -r models/* "$MODELS_DIR/"
+
+echo "🧹 Cleaning up..."
+rm -rf realesrgan-ncnn-vulkan.zip realesrgan-ncnn-vulkan models/ input.jpg input2.jpg onepiece_demo.mp4 README_ubuntu.md
+
+echo ""
+echo "════════════════════════════════════════════════════════════════"
+echo "✅ Real-ESRGAN Successfully Installed!"
+echo "════════════════════════════════════════════════════════════════"
+echo ""
+echo "Binary: $INSTALL_DIR/realesrgan-ncnn-vulkan"
+echo "Models: $MODELS_DIR"
+echo ""
+echo "Test it:"
+echo "  realesrgan-ncnn-vulkan -v"
+echo ""
+echo "Note: Make sure $INSTALL_DIR is in your PATH"
+echo "Add this to your ~/.bashrc if needed:"
+echo '  export PATH="$HOME/.local/bin:$PATH"'
+echo ""