feat(wasm): add Rust BIP32 implementation

Add WebAssembly BIP32 implementation with ECPair functionality for:
- Hierarchical Deterministic key derivation (BIP32)
- Compressed public key management
- Bitcoin message signing and verification (BIP137)
- ECDSA signing and verification

The implementation provides a minimal, secure foundation for wallet operations.

Issue: BTC-2915

Co-authored-by: llm-git <llm-git@ttll.de>

Author: OttoAllmendinger

package-lock.json

@@ -0,0 +1,10 @@
+target/
+node_modules/
+# we actually only track the .ts files
+dist/
+test/*.js
+test/*.d.ts
+js/*.js
+js/*.d.ts
+js/wasm
+.vscode

packages/wasm-bip32/.gitignore

@@ -0,0 +1,5 @@
+{
+  "extensions": ["ts", "tsx", "js", "jsx"],
+  "spec": ["test/**/*.ts"],
+  "node-option": ["import=tsx/esm", "experimental-wasm-modules"]
+}