feat: logo dans la topbar à la place de l'emoji+texte

frontend/src/components/Map/SargassesMap.jsx

@@ -2,7 +2,6 @@ import { useCallback, useEffect, useRef, useState } from 'react';
 import Map, { Layer, Marker, NavigationControl, Source } from 'react-map-gl/maplibre';
 import 'maplibre-gl/dist/maplibre-gl.css';
 import { api } from '../../api/client';
-import logoUrl from '../../assets/logo-radarsargasses971.png';
 import './SargassesMap.css';
 
 const INITIAL_VIEW = { longitude: -61.55, latitude: 16.25, zoom: 9 };
@@ -272,8 +271,6 @@ export default function SargassesMap({ onSpotSelect, selectedSpotId, activeStep,
     >
       <NavigationControl position="bottom-right" />
 
-      <img src={logoUrl} className="smap-logo" alt="Radar Sargasses 971" />
-
       {dataDate && (
         <div className="smap-freshness">
           Données du {dataDate.toLocaleDateString('fr-FR', { day: '2-digit', month: '2-digit' })}

frontend/src/components/Topbar/Topbar.css

@@ -22,15 +22,10 @@
   flex-shrink: 0;
 }
 
-.topbar__logo { font-size: 20px; }
-
-.topbar__title {
-  font-family: 'Fredoka One', cursive;
-  font-size: 17px;
-  font-weight: 400;
-  color: #f1f5f9;
-  white-space: nowrap;
-  letter-spacing: 0.02em;
+.topbar__logo-img {
+  height: 36px;
+  width: auto;
+  display: block;
 }
 
 /* ── Islands nav ── */

frontend/src/components/Topbar/Topbar.jsx

@@ -1,4 +1,5 @@
 import TimelineSlider from '../Timeline/TimelineSlider';
+import logoUrl from '../../assets/logo-radarsargasses971.png';
 import './Topbar.css';
 
 const ISLANDS = [
@@ -13,8 +14,7 @@ export default function Topbar({ activeStep, onStepChange, onIslandSelect }) {
   return (
     <header className="topbar">
       <div className="topbar__brand">
-        <span className="topbar__logo" aria-hidden="true">🌊</span>
-        <span className="topbar__title">Radar Sargasses</span>
+        <img src={logoUrl} alt="Radar Sargasses 971" className="topbar__logo-img" />
       </div>
 
       <nav className="topbar__islands" aria-label="Navigation par île">