fix(search): runSearch bricht pending Debounce ab

Enter waehrend Debounce-Fenster feuerte bislang eine zweite Fetch
fuer dieselbe Query. Race-Guard greift nicht, weil q identisch ist.
runSearch clearTimeout am Anfang behebt's, neuer Unit-Test sichert es.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/unit/search-store.test.ts

@@ -221,6 +221,22 @@ describe('SearchStore', () => {
     expect(fetchImpl.mock.calls[1][0]).toMatch(/&domains=chefkoch\.de/);
   });
 
+  it('runSearch(q) cancels pending debounce to avoid double-fetch', async () => {
+    vi.useFakeTimers();
+    const fetchImpl = mockFetch([
+      { body: { hits: [{ id: 1, title: 'immediate', description: null, image_path: null, source_domain: null, avg_stars: null, last_cooked_at: null }] } }
+    ]);
+    const store = new SearchStore({ fetchImpl, debounceMs: 300 });
+    store.query = 'meal';
+    store.runDebounced(); // schedules the 300ms timer
+    // Before the timer fires, call runSearch immediately (e.g. form submit).
+    await store.runSearch('meal');
+    expect(fetchImpl).toHaveBeenCalledTimes(1);
+    // Now advance past the original debounce — timer must not still fire.
+    await vi.advanceTimersByTimeAsync(400);
+    expect(fetchImpl).toHaveBeenCalledTimes(1);
+  });
+
   it('reSearch: immediate re-run with current query on filter change', async () => {
     vi.useFakeTimers();
     let filter = '';