test(13-08): satisfy vue-tsc -b build-mode checks in test files

npm run build runs vue-tsc -b (project references, noUncheckedIndexedAccess),
stricter than the flat --noEmit used during Task 2 verification: indexed
CustomEvent accesses need non-null assertions, the suspended-chat Promise
needs an explicit <unknown> ctor, and one unused import. 41/41 still green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

neode-ui/src/views/__tests__/chatAiuiEmbed.test.ts

@@ -112,7 +112,7 @@ describe('Chat / AIUI embed URL stability + D-14 defaults (02-07)', () => {
     expect(iframeSrc(wrapper)).toBe(before)
     // and the params are stripped so a refresh does not silently re-ask
     expect(routerReplaceMock).toHaveBeenCalled()
-    const replaceArg = routerReplaceMock.mock.calls[0][0]
+    const replaceArg = routerReplaceMock.mock.calls[0]![0]
     expect(replaceArg.query.ask).toBeUndefined()
     expect(replaceArg.query.askedAt).toBeUndefined()
     wrapper.unmount()