test(ai): rendre le test du menu mention non flaky (nettoyage d'etat + attente du fetch)

tests/frontend/ai.test.mjs

@@ -1363,6 +1363,14 @@ async function main() {
   // ── 39. Accented `@` mentions + all-vault fallback (BUG-008) ──
   await test("mention menu accepts accents and searches all vaults without a vault", async () => {
     localStorage.clear();
+    document.body.replaceChildren();
+    const stateMod = await import(pathToFileURL(path.join(JS_DIR, "state.js")).href);
+    const prevVaults = stateMod.state.allVaults;
+    const prevSelected = stateMod.state.selectedContextVault;
+    const prevCurrent = stateMod.state.currentVault;
+    stateMod.state.allVaults = [];
+    stateMod.state.selectedContextVault = null;
+    stateMod.state.currentVault = null;
     let lastUrl = "";
     globalThis.fetch = async (url) => {
       lastUrl = String(url);
@@ -1382,13 +1390,21 @@ async function main() {
     ta.value = "@café";
     ta.selectionStart = ta.selectionEnd = 5;
     b._onComposerInput();
-    await sleep(20);
     const menu = b._panel.querySelector(".bookslm-mention-menu");
+    let waited = 0;
+    while (!lastUrl.includes("tree-search") && waited < 500) {
+      await sleep(20);
+      waited += 20;
+    }
     assert.ok(!menu.classList.contains("hidden"), "accented mention keeps the menu open");
-    assert.ok(lastUrl.includes("vault=all"), "no vault -> searches all vaults");
+    assert.ok(lastUrl.includes("vault=all"),
+      `no vault -> searches all vaults (got last fetch "${lastUrl}")`);
     assert.equal(menu.querySelectorAll(".bookslm-menu-item").length, 1);
     b._panel.remove();
     localStorage.clear();
+    stateMod.state.allVaults = prevVaults;
+    stateMod.state.selectedContextVault = prevSelected;
+    stateMod.state.currentVault = prevCurrent;
   });
 
   // ── 40. Keyboard navigation in the command menu (BUG-007) ──