feat: initialize markr nostr bookmark client

- Add project structure with TypeScript, React, and Vite
- Implement nostr authentication using browser extension (NIP-07)
- Add NIP-51 compliant bookmark fetching and display
- Create minimal UI with login and bookmark components
- Integrate applesauce-core and applesauce-react libraries
- Add responsive styling with dark/light mode support
- Include comprehensive README with setup instructions

This is a minimal MVP for a nostr bookmark client that allows users to
view their bookmarks according to NIP-51 specification.

node_modules/nostr-tools/lib/esm/nip42.js

@@ -0,0 +1,18 @@
+// kinds.ts
+var ClientAuth = 22242;
+
+// nip42.ts
+function makeAuthEvent(relayURL, challenge) {
+  return {
+    kind: ClientAuth,
+    created_at: Math.floor(Date.now() / 1e3),
+    tags: [
+      ["relay", relayURL],
+      ["challenge", challenge]
+    ],
+    content: ""
+  };
+}
+export {
+  makeAuthEvent
+};