Debounce map fetch and cap feed size

src/components/Map/usePostsEngine.js

@@ -113,8 +113,8 @@ function getPostTimeMs(p) {
   return d.getTime();
 }
 
-const MAX_POOL_POSTS = 150;
-const MAX_VISIBLE_POSTS = 90;
+const MAX_POOL_POSTS = 120;
+const MAX_VISIBLE_POSTS = 70;
 
 function prunePosts(posts, center, maxCount) {
   if (!Array.isArray(posts) || posts.length <= maxCount) return posts || [];
@@ -151,6 +151,8 @@ export function usePostsEngine({
   const allPostsRef = useRef([]);
   const lastFetchRef = useRef({ center: null, radiusKm: null, filterKey: "", timeFilter: "", bounds: null });
   const delayedFetchRef = useRef(null);
+  const moveDebounceRef = useRef(null);
+  const initialLoadRef = useRef(true);
   const autoWidenRef = useRef(false);
   const [mapReady, setMapReady] = useState(false);
   const clusterModeRef = useRef(false);
@@ -656,7 +658,7 @@ export function usePostsEngine({
           lat,
           lon: lng,
           radius_km: radiusKm,
-          limit: 50,
+          limit: 40,
           bounds,
           username: username || undefined,
         });
@@ -725,9 +727,21 @@ export function usePostsEngine({
       }
     }
 
-    load();
+    const delay = initialLoadRef.current ? 0 : 2400;
+    initialLoadRef.current = false;
+    if (moveDebounceRef.current) {
+      clearTimeout(moveDebounceRef.current);
+      moveDebounceRef.current = null;
+    }
+    moveDebounceRef.current = setTimeout(() => {
+      if (!cancelled) load();
+    }, delay);
     return () => {
       cancelled = true;
+      if (moveDebounceRef.current) {
+        try { clearTimeout(moveDebounceRef.current); } catch {}
+        moveDebounceRef.current = null;
+      }
       if (delayedFetchRef.current) {
         try { clearTimeout(delayedFetchRef.current); } catch {}
         delayedFetchRef.current = null;
@@ -755,7 +769,7 @@ export function usePostsEngine({
           lat,
           lon,
           radius_km: viewParams?.radiusKm,
-          limit: 80,
+          limit: 60,
         });
         if (cancelled) return;
         const posts = Array.isArray(data?.posts) ? data.posts : [];