show TOTM popup until dismissed - forgotten commit

i forgot to commit this
basically just shows until dismissed even persistent over reloads so the user doesn't lose it the moment they navigate away or if they load the page and close it immediately

src/types/storage.ts

@@ -36,7 +36,12 @@ export interface SettingsState {
   engageParentsAnnouncementShown?: boolean;
   /** One-time announcement: BS Cloud automatic settings sync (last in startup popup queue). */
   bsCloudAutoSyncAnnouncementShown?: boolean;
-  /** ID of the last Theme of the Month entry shown to the user (shows once per new entry). */
+  /**
+   * Calendar month (`YYYY-MM`) for which the user dismissed the Theme of the Month
+   * popup via "Don't show again" (not a normal Close).
+   */
+  themeOfTheMonthDismissedMonth?: string;
+  /** @deprecated Migrated away; no longer read. */
   themeOfTheMonthLastSeenId?: string;
   /** Permanently disables Theme of the Month startup prompts. */
   themeOfTheMonthDisabled?: boolean;