lots of login dialog and nostr subsription relate updates

src/lib/nostr.ts

@@ -105,4 +105,19 @@ export function npubToHex(npub: string): string {
 
 export function hexToNpub(hex: string): string {
   return window.NostrTools.nip19.npubEncode(hex)
+}
+
+export function isValidPrivateKey(key: string): boolean {
+  try {
+    if (!/^[0-9a-fA-F]{64}$/.test(key)) {
+      return false
+    }
+    return true
+  } catch {
+    return false
+  }
+}
+
+export function formatPrivateKey(key: string): string {
+  return key.trim().toLowerCase()
 }