feat: add monitoring settings tab, workbench view, and inspection alert improvements

infrastructure/config/storageKeys.ts

@@ -2,6 +2,8 @@
 export const STORAGE_KEY_PRODUCT_NAME = 'netcatty_product_name_v1';
 /** User-editable topology monitoring dashboard title. */
 export const STORAGE_KEY_MONITORING_DASHBOARD_TITLE = 'netcatty_monitoring_dashboard_title_v1';
+/** User-selected topology map background filename (relative to userData/monitoring/maps). */
+export const STORAGE_KEY_MONITORING_MAP_BG_SELECTED = 'netcatty_monitoring_map_bg_selected_v1';
 /** User-editable product name shown in inspection PDF reports. */
 export const STORAGE_KEY_REPORT_PRODUCT_NAME = 'netcatty_report_product_name_v1';