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/components/SchoolDetailView.tsx

@@ -44,16 +44,16 @@ export function SchoolDetailView({ schoolInfo, yearlyData, absenceData }: School
             <div className={styles.meta}>
               {schoolInfo.local_authority && (
                 <span className={styles.metaItem}>
-                  📍 {schoolInfo.local_authority}
+                  {schoolInfo.local_authority}
                 </span>
               )}
               {schoolInfo.school_type && (
                 <span className={styles.metaItem}>
-                  🏫 {schoolInfo.school_type}
+                  {schoolInfo.school_type}
                 </span>
               )}
               <span className={styles.metaItem}>
-                🔢 URN: {schoolInfo.urn}
+                URN: {schoolInfo.urn}
               </span>
             </div>
             {schoolInfo.address && (
@@ -216,7 +216,7 @@ export function SchoolDetailView({ schoolInfo, yearlyData, absenceData }: School
 
           {/* Maths Metrics */}
           <div className={styles.metricGroup}>
-            <h3 className={styles.metricGroupTitle}>🔢 Mathematics</h3>
+            <h3 className={styles.metricGroupTitle}>Mathematics</h3>
             <div className={styles.metricTable}>
               {latestResults.maths_expected_pct !== null && (
                 <div className={styles.metricRow}>