Improve professional appearance: logo, favicon, and remove emoji icons

1. Added original favicon
   - Copied favicon.svg from original frontend
   - Added favicon reference to layout metadata
   - Professional icon with brand colors

2. Updated logo in navigation
   - Replaced emoji with proper SVG logo from original design
   - Uses circular target design with crosshairs
   - Matches brand identity with coral accent color

3. Removed emoji icons throughout app for professional look
   - Removed 📍 (location pin) from school locations
   - Removed 🏫 (school building) from school types
   - Removed 🔢 from URN labels and section headings
   - Kept meaningful symbols (✓, +) in buttons only
   - Updated map popup button color to brand coral (#e07256)

Components updated:
- Navigation: Professional SVG logo
- HomeView: Clean location banner
- SchoolDetailView: No decorative emojis in metadata
- ComparisonView: Text-only school information
- SchoolSearchModal: Clean school listings
- LeafletMapInner: Professional map popups

Result: More polished, professional appearance suitable for
educational data platform

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

nextjs-app/app/layout.tsx

@@ -28,6 +28,11 @@ export const metadata: Metadata = {
   keywords: 'school comparison, KS2 results, primary school performance, England schools, SATs results',
   authors: [{ name: 'SchoolCompare' }],
   manifest: '/manifest.json',
+  icons: {
+    icon: '/favicon.svg',
+    shortcut: '/favicon.svg',
+    apple: '/favicon.svg',
+  },
   openGraph: {
     type: 'website',
     title: 'SchoolCompare | Compare Primary School Performance',