perf: spots/overview — 100+ requêtes individuelles → 1 requête cachée 30 min

Avant : SargassesMap faisait 1 appel /api/spots (API Platform) puis
N appels /api/spots/{id}/score (un par spot, ~100+ pour la Guadeloupe).

Après : un seul GET /api/spots/overview (LATERAL JOIN spots+scores)
avec Cache-Control: public, max-age=1800, stale-while-revalidate=300.

Les marqueurs colorés s'affichent immédiatement depuis la réponse unique ;
/api/spots/{id}/score n'est appelé qu'au clic sur un spot (SpotPanel).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/Controller/SpotScoreController.php

@@ -20,6 +20,46 @@ class SpotScoreController extends AbstractController
         private Connection             $connection,
     ) {}
 
+    /**
+     * GET /api/spots/overview
+     *
+     * Retourne tous les spots avec leur dernier score en UNE seule requête.
+     * Remplace les N appels individuels à /api/spots/{id}/score pour le rendu
+     * initial de la carte.
+     *
+     * Cache HTTP 30 min (scores mis à jour au max 1-2×/jour par ingestion).
+     */
+    #[Route('/overview', name: 'overview', methods: ['GET'])]
+    public function overview(): JsonResponse
+    {
+        $rows = $this->connection->fetchAllAssociative(
+            "SELECT
+                cp.id::text,
+                cp.name,
+                cp.type,
+                cp.region,
+                ST_X(cp.geometry::geometry)  AS longitude,
+                ST_Y(cp.geometry::geometry)  AS latitude,
+                ist.score,
+                ist.level,
+                ROUND(CAST(ist.distance_to_nearest_sargassum AS numeric), 2) AS distance_km
+             FROM coastal_point cp
+             LEFT JOIN LATERAL (
+                 SELECT score, level, distance_to_nearest_sargassum
+                 FROM impact_score
+                 WHERE coastal_point_id = cp.id
+                 ORDER BY timestamp DESC
+                 LIMIT 1
+             ) ist ON true
+             ORDER BY cp.name"
+        );
+
+        $response = $this->json($rows);
+        $response->headers->set('Cache-Control', 'public, max-age=1800, stale-while-revalidate=300');
+
+        return $response;
+    }
+
     /**
      * GET /api/spots/{id}/score
      *

frontend/src/api/client.js

@@ -25,7 +25,7 @@ async function post(path, body) {
 
 export const api = {
   spots: {
-    list: ()       => get('/spots'),
+    overview: ()       => get('/spots/overview'),   // tous les spots + score en 1 requête cachée
     get:      (id)     => get(`/spots/${id}`),
     score:    (id, at) => get(`/spots/${id}/score`, { at }),
   },

frontend/src/components/Map/SargassesMap.jsx

@@ -179,8 +179,9 @@ function SpotMarker({ level, scoreValue, scoreDist, isSelected, name }) {
 
 export default function SargassesMap({ onSpotSelect, selectedSpotId, activeStep, flyToTarget }) {
   const mapRef = useRef(null);
+  // spots : [{ id, name, type, region, longitude, latitude, score, level, distance_km }]
   const [spots,        setSpots]        = useState([]);
-  const [spotScores,   setSpotScores]   = useState({});
+  const [spotScores,   setSpotScores]   = useState({});  // id → { level, value, distance }
   const [viewState,    setViewState]    = useState(INITIAL_VIEW);
   const [layerOpacity, setLayerOpacity] = useState(1);
   const [mapStyle,     setMapStyle]     = useState(null);   // null = style not yet ready
@@ -212,28 +213,28 @@ export default function SargassesMap({ onSpotSelect, selectedSpotId, activeStep,
     return () => ctrl.abort();
   }, []);
 
-  // Load coastal spots once
+  // Charge tous les spots + scores en UNE requête (cachée 30 min côté serveur)
   useEffect(() => {
-    api.spots.list()
+    api.spots.overview()
-      .then(data => setSpots(Array.isArray(data) ? data : (data['hydra:member'] ?? data.member ?? [])))
+      .then(rows => {
+        if (!Array.isArray(rows)) return;
+        setSpots(rows);
+        // Pré-remplir spotScores depuis la même réponse — aucune requête supplémentaire
+        const scores = {};
+        rows.forEach(r => {
+          if (r.level) {
+            scores[r.id] = {
+              level:    r.level,
+              value:    r.score   ?? 0,
+              distance: r.distance_km ?? null,
+            };
+          }
+        });
+        setSpotScores(scores);
+      })
       .catch(console.error);
   }, []);
 
-  // Load scores progressively for marker colors
-  useEffect(() => {
-    if (!spots.length) return;
-    spots.forEach(s => {
-      api.spots.score(s.id)
-        .then(d => {
-          const level    = d?.score?.level;
-          const value    = d?.score?.value ?? 0;
-          const distance = d?.score?.distance ?? null;
-          if (level) setSpotScores(prev => ({ ...prev, [s.id]: { level, value, distance } }));
-        })
-        .catch(() => {});
-    });
-  }, [spots]);
-
   // Fade transition on step change
   useEffect(() => {
     setLayerOpacity(0);