made the cache more persistent

src/lib/utils/npubCache.ts

@@ -4,6 +4,47 @@ export type NpubMetadata = NostrProfile;
 
 class NpubCache {
   private cache: Record<string, NpubMetadata> = {};
+  private readonly storageKey = 'alexandria_npub_cache';
+  private readonly maxAge = 24 * 60 * 60 * 1000; // 24 hours in milliseconds
+
+  constructor() {
+    this.loadFromStorage();
+  }
+
+  private loadFromStorage(): void {
+    try {
+      if (typeof window !== 'undefined') {
+        const stored = localStorage.getItem(this.storageKey);
+        if (stored) {
+          const data = JSON.parse(stored) as Record<string, { profile: NpubMetadata; timestamp: number }>;
+          const now = Date.now();
+          
+          // Filter out expired entries
+          for (const [key, entry] of Object.entries(data)) {
+            if (entry.timestamp && (now - entry.timestamp) < this.maxAge) {
+              this.cache[key] = entry.profile;
+            }
+          }
+        }
+      }
+    } catch (error) {
+      console.warn('Failed to load npub cache from storage:', error);
+    }
+  }
+
+  private saveToStorage(): void {
+    try {
+      if (typeof window !== 'undefined') {
+        const data: Record<string, { profile: NpubMetadata; timestamp: number }> = {};
+        for (const [key, profile] of Object.entries(this.cache)) {
+          data[key] = { profile, timestamp: Date.now() };
+        }
+        localStorage.setItem(this.storageKey, JSON.stringify(data));
+      }
+    } catch (error) {
+      console.warn('Failed to save npub cache to storage:', error);
+    }
+  }
 
   get(key: string): NpubMetadata | undefined {
     return this.cache[key];
@@ -11,6 +52,7 @@ class NpubCache {
 
   set(key: string, value: NpubMetadata): void {
     this.cache[key] = value;
+    this.saveToStorage();
   }
 
   has(key: string): boolean {
@@ -20,6 +62,7 @@ class NpubCache {
   delete(key: string): boolean {
     if (key in this.cache) {
       delete this.cache[key];
+      this.saveToStorage();
       return true;
     }
     return false;
@@ -37,6 +80,7 @@ class NpubCache {
 
   clear(): void {
     this.cache = {};
+    this.saveToStorage();
   }
 
   size(): number {