feat: Add PWA assets and metadata for iOS Safari installation

- Generate app icons in multiple sizes (192x192, 512x512, 180x180, 32x32)
- Create favicon and apple-touch-icon SVG files
- Add comprehensive PWA meta tags in app layout
- Configure theme color (#3B82F6) and background color
- Update manifest.json with icon references (PNG and SVG)
- Create icon generation scripts (SVG and PNG conversion)
- Add browser-based PNG icon generator (HTML)
- Create comprehensive PWA testing guide
- Add icon setup documentation

Requirements: 4.1, 4.2
Task: 13. Add PWA assets and metadata

public/apple-touch-icon.svg

@@ -0,0 +1,7 @@
+<svg width="180" height="180" viewBox="0 0 180 180" xmlns="http://www.w3.org/2000/svg">
+  <rect width="180" height="180" rx="45" fill="#3B82F6"/>
+  <path d="M54 90L81 117L125.99999999999999 62.99999999999999" 
+        stroke="white" stroke-width="14.4" stroke-linecap="round" stroke-linejoin="round"/>
+  <rect x="45" y="108" width="90" height="14.4" rx="3.6" fill="white"/>
+  <rect x="45" y="129.6" width="72" height="14.4" rx="3.6" fill="white"/>
+</svg>