[fix](trx-rs): frost main view on trx-server disconnect

Nudge state watch when server_connected goes false so SSE delivers the change. Frontend applies a desaturated frost + banner instead of a blocking overlay, keeping the last-known state visible.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/trx-frontend/trx-frontend-http/assets/web/index.html

@@ -96,6 +96,7 @@
       <div id="auth-role" style="margin-top: 1rem; color: var(--text-muted); font-size: 0.85rem; display: none;"></div>
     </div>
     <div id="tab-main" class="tab-panel">
+    <div id="server-lost-banner" aria-live="assertive"><span class="banner-dot"></span>trx-server connection lost — waiting for reconnect</div>
     <div id="loading" style="text-align:center; padding:2rem 0;">
       <div id="loading-title" style="margin-bottom:0.4rem; font-size:1.1rem; font-weight:600;">Initializing (rig)…</div>
       <div id="loading-sub" style="color:#9aa4b5;"></div>