fix: local search results now render before full pipeline completes

The full Search() call was blocking the render even after SearchLocal
returned results — both awaits ran in the same async function, and
Wails may serialize Go calls preventing the microtask yield from
triggering a render.

Split executeFullSearch into a separate async method invoked with
void (fire-and-forget). executeSearch now returns after SearchLocal
completes, letting Lit render the local results immediately. The
full pipeline results replace them when ready.

frontend/src/components/explore-view/explore-view.ts

@@ -543,6 +543,11 @@ export class ExploreView extends LitElement {
         }
 
         // Phase 2: full pipeline (MB + LB + reranking).
+        // Fire-and-forget so the local results render immediately.
+        void this.executeFullSearch(version, query, startTime);
+    }
+
+    private async executeFullSearch(version: number, query: string, startTime: number) {
         try {
             const result = await Search(query);