fix(FN-2292): increase mobile toast clearance and stabilize related tests

- Raise mobile .toast-container bottom offset by adding --space-2xl to clear footer/nav overlap
- Update utility-mobile CSS regression assertion to match the new toast offset formula
- Extend build-exe test timeout from 20s to 90s to reduce flaky CLI packaging failures

packages/cli/src/__tests__/build-exe.test.ts

@@ -119,7 +119,7 @@ describe("build-exe", () => {
         cleanup();
       }
     },
-    20_000,
+    90_000,
   );
 
   it("binary runs 'task list' without crashing", () => {