Upgrade to @noble/curves ^2.0.1 and @noble/hashes ^2.0.1

This commit upgrades the noble cryptography dependencies to v2.0.1, which includes:

Breaking changes addressed:
- Updated all @noble imports to include .js extensions (required by v2 ESM-only API)
- Changed @noble/hashes/sha256 to @noble/hashes/sha2.js across 8 files
- Fixed secp256k1 API changes: methods now require Uint8Array instead of hex strings
- Updated schnorr.utils.randomPrivateKey() to schnorr.utils.randomSecretKey()

Files modified (27 total):
- package.json: Bump dependency versions
- Source files (12): pure.ts, nip04.ts, nip06.ts, nip13.ts, nip19.ts, nip44.ts,
  nip49.ts, nip77.ts, nip98.ts, nipb7.ts, utils.ts, wasm.ts
- Test files (14): All corresponding test files updated

Benefits:
- Latest security updates from audited noble libraries
- Smaller bundle sizes from v2 optimizations
- Future-proof ESM-only compatibility
- All tests passing

Co-authored-by: OpenCode <opencode@anomalyco.com>

package.json

@@ -237,8 +237,8 @@
   "license": "Unlicense",
   "dependencies": {
     "@noble/ciphers": "^0.5.1",
-    "@noble/curves": "1.2.0",
-    "@noble/hashes": "1.3.1",
+    "@noble/curves": "^2.0.1",
+    "@noble/hashes": "^2.0.1",
     "@scure/base": "1.1.1",
     "@scure/bip32": "1.3.1",
     "@scure/bip39": "1.2.1",