Add persistent OLED UI settings and recovery

src/local_status_ui.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include "esp_err.h"
+#include "local_ui_config.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -14,7 +15,11 @@ extern "C" {
  * task never becomes a broker client or serial writer. The OLED and buttons
  * are optional, so a missing display is not an error.
  */
-esp_err_t local_status_ui_start(void);
+esp_err_t local_status_ui_start(const local_ui_config_t *config);
+
+/* Runtime settings are copied atomically and never expose display-frame ownership. */
+esp_err_t local_status_ui_get_config(local_ui_config_t *config);
+esp_err_t local_status_ui_apply_config(const local_ui_config_t *config);
 
 /* Preserve a manually selected display diagnostic for a bounded interval. */
 void local_status_ui_hold_for_diagnostics(void);