[fix](trx-frontend-http): restore global rig update in select_rig

The previous commit conditionally skipped updating remote_active_rig_id
when session_id was provided, but the remote client reads the global to
route commands to the correct rig on trx-server. Restore the
unconditional global update; cross-tab SSE isolation is handled by the
rig_id query param on /events and the JS-side guard in applyRigList.

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/src/api.rs

@@ -1619,14 +1619,17 @@ pub async fn select_rig(
         )));
     }
 
-    // Update per-session rig selection if session_id is provided, otherwise
-    // update the global default (for non-session-aware clients).
+    // Always update the global active rig — the remote client uses it to
+    // route commands to the correct rig on the server.
+    if let Ok(mut active) = context.remote_active_rig_id.lock() {
+        *active = Some(rig_id.to_string());
+    }
+
+    // Update per-session rig selection if session_id is provided.
     if let Some(ref sid) = query.session_id {
         if let Ok(uuid) = Uuid::parse_str(sid) {
             session_rig_mgr.set_rig(uuid, rig_id.to_string());
         }
-    } else if let Ok(mut active) = context.remote_active_rig_id.lock() {
-        *active = Some(rig_id.to_string());
     }
 
     // Broadcast the channel list for the newly selected rig so all SSE