[feat] add dedicated privacy screen controls

apps/desktop/src/gui/runtime/privacy_control_state.h

@@ -0,0 +1,58 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2026-09-12
+ * Copyright (c) 2026 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _PRIVACY_CONTROL_STATE_H_
+#define _PRIVACY_CONTROL_STATE_H_
+
+#include <cstdint>
+
+#include "remote_action.h"
+
+namespace crossdesk {
+
+struct PrivacyControlState {
+  bool active = false;
+  bool enabled = false;
+  bool off = false;
+  bool unsupported = false;
+  bool warning = false;
+  bool stale = false;
+  bool timeout = false;
+  bool can_toggle = false;
+};
+
+// Use the same host-confirmed state for presentation and command admission.
+// An engaged or failed screen can still be disabled when its status goes stale.
+inline PrivacyControlState GetPrivacyControlState(
+    const PrivacyStatus& status, bool received, bool command_pending,
+    uint64_t status_age_ms, uint64_t command_age_ms) {
+  PrivacyControlState result;
+  result.timeout = command_pending && command_age_ms > 15000;
+  result.stale = received && status_age_ms > 5000;
+  const bool request_pending = command_pending && !result.timeout;
+  const bool fresh = received && !result.stale;
+  result.active = status.overlay_active || status.remote_paused ||
+                  status.state == PrivacyState::on ||
+                  status.state == PrivacyState::starting ||
+                  status.state == PrivacyState::stopping ||
+                  status.state == PrivacyState::failed;
+  // A command in flight only gates repeated clicks; it adds no display state.
+  result.enabled = fresh && !result.timeout &&
+                   status.state == PrivacyState::on && status.overlay_active &&
+                   !status.remote_paused;
+  result.off = fresh && !result.timeout &&
+               status.state == PrivacyState::off && !result.active;
+  result.unsupported = received && !status.supported;
+  result.warning = result.timeout || result.stale ||
+      (received && status.state == PrivacyState::failed);
+  result.can_toggle = !request_pending &&
+                      (result.active || (fresh && status.supported));
+  return result;
+}
+
+}  // namespace crossdesk
+
+#endif

apps/desktop/src/gui/runtime/remote_session.h

@@ -161,7 +161,6 @@ struct RemoteSession {
   PrivacyStatus privacy_status_{};
   bool privacy_status_received_ = false;
   bool privacy_command_pending_ = false;
-  bool privacy_block_local_input_ = true;
   uint64_t privacy_command_tick_ = 0;
   uint32_t privacy_request_revision_ = 0;
   uint64_t privacy_status_tick_ = 0;