fix(tests): deflake recipe modal resource item tests by disposing modal instances

RecipeModal instances keep fire-and-forget async chains (hydration
re-renders, mark-hash-invalid re-renders, 500ms reconnect/restore
re-renders) and deferred DOM wiring timers alive across tests. On slow
CI runners these land in the next test's window and overwrite or re-wire
the shared document.body with stale content and stale instance handlers,
failing a different test on every run.

Add a tracked-timer helper and a dispose() teardown hook to RecipeModal:
pending deferred work is cancelled, in-flight async chains become no-ops
after disposal, and the global click listener is detached. The test
afterEach now disposes every modal instance, making the file hermetic.

tests/frontend/components/recipeModal.resourceItems.test.js

@@ -210,7 +210,11 @@ describe('RecipeModal resource item interactions', () => {
   });
 
   afterEach(() => {
-    createdModals.forEach(recipeModal => recipeModal.cleanupNavigationShortcuts());
+    // dispose() marks each modal instance dead: pending deferred timers
+    // (wiring, 500ms reconnect re-renders) are cancelled and in-flight
+    // async chains become no-ops, so nothing from this test can touch the
+    // DOM of the next one.
+    createdModals.forEach(recipeModal => recipeModal.dispose());
     createdModals.length = 0;
     document.body.innerHTML = '';
     delete global.modalManager;