feat: gossip model

packages/app/src/Cache/UserRelayCache.ts

@@ -0,0 +1,18 @@
+import { db, UsersRelays } from "Db";
+import FeedCache from "./FeedCache";
+
+class UsersRelaysCache extends FeedCache<UsersRelays> {
+  constructor() {
+    super("UserRelays", db.userRelays);
+  }
+
+  key(of: UsersRelays): string {
+    return of.pubkey;
+  }
+
+  takeSnapshot(): Array<UsersRelays> {
+    return [...this.cache.values()];
+  }
+}
+
+export const UserRelays = new UsersRelaysCache();