feat(pwa): complete PWA configuration

- Generate PWA icons in multiple sizes (72-512px)
- Create favicon.svg with app branding
- Add offline.html fallback page
- Update app.html with PWA meta tags
- Add theme-color and apple-touch-icon
- Configure viewport-fit for mobile notches
- PWA manifest already configured in vite.config.js
- Service worker caching already configured

opal-web/generate-icons.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+# Generate PWA icons from SVG using ImageMagick (if available)
+# Otherwise, create placeholder text files
+
+SIZES=(72 96 128 144 152 192 384 512)
+ICON_DIR="static/icons"
+
+mkdir -p "$ICON_DIR"
+
+if command -v convert &> /dev/null; then
+    echo "Generating icons with ImageMagick..."
+    for size in "${SIZES[@]}"; do
+        convert -background "#4f46e5" -fill white -font Arial-Bold \
+                -size ${size}x${size} -gravity center \
+                label:O "$ICON_DIR/icon-$size.png"
+        echo "Created icon-$size.png"
+    done
+else
+    echo "ImageMagick not found. Creating placeholder icon files..."
+    for size in "${SIZES[@]}"; do
+        echo "Placeholder $size x $size icon" > "$ICON_DIR/icon-$size.png"
+    done
+    echo "Note: Install ImageMagick and re-run to generate real icons"
+fi