Skip wasted discovery-section queries

Two related gates on the unified discovery sections:

- PledgesDiscoverySection: the chronological useActions({ limit: 300 })
  query only feeds the idle render branch (via idlePledges), but it
  was firing in active-search mode too. Active mode renders searchHits
  from useNip50Search, which never reads rawActions. On every keystroke
  that activates search we were burning a 300-event relay round-trip
  whose results went nowhere. Gate the query on !isSearching so the
  fetch happens only when the idle branch can actually consume it.

- CampaignsDiscoverySection: align the featured-coords useCampaigns
  query's enabled flag with the pledges section's pattern. useCampaigns
  already short-circuits on an empty coordinates array, so this is
  purely about not creating an empty cache entry when moderators have
  curated nothing — but it removes a small asymmetry that would have
  made the next reviewer second-guess which pattern is intentional.

src/components/discovery/CampaignsDiscoverySection.tsx

@@ -124,7 +124,11 @@ export function CampaignsDiscoverySection({
   const { data: featuredCampaigns } = useCampaigns({
     coordinates: featuredCoords,
     limit: featuredCoords.length || 1,
-    enabled: moderationReady,
+    // Mirrors the pledges section's pattern: don't enable the query
+    // when there are no coords to fetch. `useCampaigns` already
+    // short-circuits internally on an empty `coordinates` array, so
+    // this is purely about not creating a meaningless cache entry.
+    enabled: moderationReady && featuredCoords.length > 0,
   });
 
   const showHiddenValue = showHiddenProp?.value ?? false;

src/components/discovery/PledgesDiscoverySection.tsx

@@ -123,9 +123,18 @@ export function PledgesDiscoverySection({
     },
   });
 
+  // Chronological feed that backs the idle grid (and the
+  // featured-then-chronological fallback). Gated on `!isSearching`
+  // because the search branch renders `searchHits` instead and never
+  // reads `rawActions` / `actions` — leaving this query enabled during
+  // search burns a 300-event relay round-trip on every keystroke that
+  // activates the search view. The idle branch is the only consumer,
+  // and the idle branch only renders when `!isSearching`, so this
+  // gate strictly removes wasted work.
   const { data: rawActions, isLoading: actionsLoading } = useActions({
     countryCode: filters.country,
     limit: 300,
+    enabled: !isSearching,
   });
 
   const { data: pledgeModeration, isReady: pledgeModerationReady } =