[fix] show truthful signaling recovery state and pin safe retries

apps/desktop/src/gui/application/signal_connection_indicator.h

@@ -0,0 +1,38 @@
+#ifndef CROSSDESK_SIGNAL_CONNECTION_INDICATOR_H_
+#define CROSSDESK_SIGNAL_CONNECTION_INDICATOR_H_
+
+#include <chrono>
+#include <optional>
+
+namespace crossdesk {
+
+// Presentation state only. The actual connected flag remains authoritative
+// for actions and other UI consumers, including the announcement inbox.
+class SignalConnectionIndicator {
+ public:
+  using Clock = std::chrono::steady_clock;
+
+  bool Update(bool connected, Clock::time_point now = Clock::now()) {
+    if (connected) {
+      disconnected_at_.reset();
+    } else if (was_connected_) {
+      disconnected_at_ = now;
+    }
+    was_connected_ = connected;
+    return disconnected_at_ &&
+           now - *disconnected_at_ < std::chrono::seconds(10);
+  }
+
+  void Reset() {
+    was_connected_ = false;
+    disconnected_at_.reset();
+  }
+
+ private:
+  bool was_connected_ = false;
+  std::optional<Clock::time_point> disconnected_at_;
+};
+
+}  // namespace crossdesk
+
+#endif