fix(gif): prevent suggestion list flicker with keepPreviousData

When the throttled autocomplete query changes, React Query briefly
returns undefined for the new key, causing the suggestion list to
flash hidden then visible. keepPreviousData holds the old suggestions
until the new response arrives.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/state/queries/klipy.ts

@@ -94,6 +94,7 @@ export function useKlipyAutocompleteQuery(
     queryFn: () => fetchKlipyAutocomplete(query),
     enabled: query.length > 0 && options?.enabled !== false,
     staleTime: STALE.HOURS.ONE,
+    placeholderData: keepPreviousData,
   })
 }