fix: console not connected when fast-lane RPC still connecting

The console tab was passed fast_rpc_ even before its async connection
completed, causing 'Not connected to daemon' errors despite the main
RPC being connected and sync data flowing. Fall back to the main
rpc_/worker_ until fast_rpc_ reports isConnected().

src/app.cpp

@@ -1108,9 +1108,10 @@ void App::render()
         case ui::NavPage::Console:
             // Use fast-lane worker for console commands to avoid head-of-line
             // blocking behind the consolidated refreshData() batch.
+            // Fall back to main rpc/worker if fast-lane hasn't connected yet.
             console_tab_.render(embedded_daemon_.get(),
-                fast_rpc_ ? fast_rpc_.get() : rpc_.get(),
-                fast_worker_ ? fast_worker_.get() : worker_.get(),
+                (fast_rpc_ && fast_rpc_->isConnected()) ? fast_rpc_.get() : rpc_.get(),
+                (fast_rpc_ && fast_rpc_->isConnected() && fast_worker_) ? fast_worker_.get() : worker_.get(),
                 xmrig_manager_.get());
             break;
         case ui::NavPage::Settings: