[fix](trx-frontend-http): make /status respect per-tab rig selection

pollFreshSnapshot() fetches GET /status on every SSE connect/reconnect,
but /status always returned the global selected rig's state, overwriting
the per-tab display with whichever rig was last switched to globally.

Now pollFreshSnapshot passes rig_id as a query param and the /status
endpoint uses the per-rig watch channel when provided, matching the
/events behavior for true per-tab rig isolation.

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/app.js

@@ -3163,7 +3163,10 @@ function scheduleReconnect(delayMs = 1000) {
 
 async function pollFreshSnapshot() {
   try {
-    const resp = await fetch("/status", { cache: "no-store" });
+    const statusUrl = lastActiveRigId
+      ? `/status?rig_id=${encodeURIComponent(lastActiveRigId)}`
+      : "/status";
+    const resp = await fetch(statusUrl, { cache: "no-store" });
     if (!resp.ok) return;
     const data = await resp.json();
     render(data);