Add deterministic daily weather brief

lib/push-store.ts

@@ -3,6 +3,7 @@ import type { WarningPushSubscription } from "@/types/notifications";
 interface PushStore {
   subscriptions: Map<string, WarningPushSubscription>;
   sentWarningIds: Map<string, Set<string>>;
+  sentMorningBriefDates: Map<string, Set<string>>;
 }
 
 const globalStore = globalThis as typeof globalThis & { __wtrPushStore?: PushStore };
@@ -12,6 +13,7 @@ function getStore() {
     globalStore.__wtrPushStore = {
       subscriptions: new Map(),
       sentWarningIds: new Map(),
+      sentMorningBriefDates: new Map(),
     };
   }
   return globalStore.__wtrPushStore;
@@ -25,6 +27,7 @@ export function removePushSubscription(endpoint: string) {
   const store = getStore();
   store.subscriptions.delete(endpoint);
   store.sentWarningIds.delete(endpoint);
+  store.sentMorningBriefDates.delete(endpoint);
 }
 
 export function getPushSubscriptions() {
@@ -53,3 +56,14 @@ export function pruneSentWarnings(activeWarningIds: Set<string>) {
     });
   });
 }
+
+export function hasSentMorningBrief(endpoint: string, dateKey: string) {
+  return getStore().sentMorningBriefDates.get(endpoint)?.has(dateKey) ?? false;
+}
+
+export function markMorningBriefSent(endpoint: string, dateKey: string) {
+  const store = getStore();
+  const sentDates = store.sentMorningBriefDates.get(endpoint) ?? new Set<string>();
+  sentDates.add(dateKey);
+  store.sentMorningBriefDates.set(endpoint, sentDates);
+}