fix: announce connection status to assistive technology

Add role="status" and aria-live="polite" to the connection
status section so screen readers announce test results.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/views/ConnectionPanelView.vue

@@ -41,6 +41,8 @@
       <!-- Connection status -->
       <section
         v-if="httpStatus !== null || wsStatus !== null"
+        role="status"
+        aria-live="polite"
         class="flex flex-col gap-2 rounded-md bg-neutral-800/50 p-3"
       >
         <h2