ask_operator tool: non-blocking; operator answer arrives as helper event

new mcp tool on the manager surface that queues a question on the
dashboard and returns the question id immediately. operator submits an
answer via /answer-question/<id>; the dashboard fires
HelperEvent::OperatorAnswered { id, question, answer } into the manager
inbox so the next turn picks it up.

also: fix async-form button stuck on spinner after successful submit
(refreshState skipped re-rendering, so the button was never re-enabled).

hive-ag3nt/assets/app.js

@@ -48,6 +48,10 @@
       }
       // Clear text inputs the operator typed into (the form value was sent).
       f.querySelectorAll('input[type="text"], input:not([type])').forEach((i) => { i.value = ''; });
+      // Re-enable the button — refreshState() often skips re-rendering the
+      // form (status unchanged), so without this the spinner sticks and
+      // the operator can't submit again.
+      if (btn) { btn.disabled = false; btn.innerHTML = original; }
       refreshState();
     } catch (err) {
       alert('action failed: ' + err);