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/public/favicon.svg

@@ -0,0 +1,6 @@
+<svg viewBox="0 0 40 40" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <rect width="40" height="40" rx="8" fill="#1a1612"/>
+  <circle cx="20" cy="20" r="14" stroke="#e07256" stroke-width="2"/>
+  <path d="M20 8L20 32M12 14L28 14M10 20L30 20M12 26L28 26" stroke="#e07256" stroke-width="1.5" stroke-linecap="round"/>
+  <circle cx="20" cy="20" r="3" fill="#e07256"/>
+</svg>