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/nip06.js

@@ -0,0 +1,61 @@
+// nip06.ts
+import { bytesToHex } from "@noble/hashes/utils";
+import { wordlist } from "@scure/bip39/wordlists/english";
+import { generateMnemonic, mnemonicToSeedSync, validateMnemonic } from "@scure/bip39";
+import { HDKey } from "@scure/bip32";
+var DERIVATION_PATH = `m/44'/1237'`;
+function privateKeyFromSeedWords(mnemonic, passphrase, accountIndex = 0) {
+  let root = HDKey.fromMasterSeed(mnemonicToSeedSync(mnemonic, passphrase));
+  let privateKey = root.derive(`${DERIVATION_PATH}/${accountIndex}'/0/0`).privateKey;
+  if (!privateKey)
+    throw new Error("could not derive private key");
+  return privateKey;
+}
+function accountFromSeedWords(mnemonic, passphrase, accountIndex = 0) {
+  const root = HDKey.fromMasterSeed(mnemonicToSeedSync(mnemonic, passphrase));
+  const seed = root.derive(`${DERIVATION_PATH}/${accountIndex}'/0/0`);
+  const publicKey = bytesToHex(seed.publicKey.slice(1));
+  const privateKey = seed.privateKey;
+  if (!privateKey || !publicKey) {
+    throw new Error("could not derive key pair");
+  }
+  return { privateKey, publicKey };
+}
+function extendedKeysFromSeedWords(mnemonic, passphrase, extendedAccountIndex = 0) {
+  let root = HDKey.fromMasterSeed(mnemonicToSeedSync(mnemonic, passphrase));
+  let seed = root.derive(`${DERIVATION_PATH}/${extendedAccountIndex}'`);
+  let privateExtendedKey = seed.privateExtendedKey;
+  let publicExtendedKey = seed.publicExtendedKey;
+  if (!privateExtendedKey && !publicExtendedKey)
+    throw new Error("could not derive extended key pair");
+  return { privateExtendedKey, publicExtendedKey };
+}
+function accountFromExtendedKey(base58key, accountIndex = 0) {
+  let extendedKey = HDKey.fromExtendedKey(base58key);
+  let version = base58key.slice(0, 4);
+  let child = extendedKey.deriveChild(0).deriveChild(accountIndex);
+  let publicKey = bytesToHex(child.publicKey.slice(1));
+  if (!publicKey)
+    throw new Error("could not derive public key");
+  if (version === "xprv") {
+    let privateKey = child.privateKey;
+    if (!privateKey)
+      throw new Error("could not derive private key");
+    return { privateKey, publicKey };
+  }
+  return { publicKey };
+}
+function generateSeedWords() {
+  return generateMnemonic(wordlist);
+}
+function validateWords(words) {
+  return validateMnemonic(words, wordlist);
+}
+export {
+  accountFromExtendedKey,
+  accountFromSeedWords,
+  extendedKeysFromSeedWords,
+  generateSeedWords,
+  privateKeyFromSeedWords,
+  validateWords
+};