build: fix wasm-bindgen deprecation warning

[gustavovalverde]

Problem

Console warning appears when using @serenity-kit/opaque: "using deprecated parameters for the initialization function; pass a single object instead"

Fixes #150

Root Cause

This was caused by two issues:

1. Outdated wasm-bindgen version: Project was using 0.2.105, which had a bug where passing WASM data to init function incorrectly triggered deprecation warnings.

2. Old initialization pattern: The template was using deprecated API call pattern init(wasmData()) instead of new object-based format.

Solution

Updated three files to resolve the issue:

1. Cargo.toml: Upgraded wasm-bindgen from 0.2.105 to 0.2.106
2. bin/templates/index.ts: Fixed initialization pattern from init(wasmData()) to init({module_or_path: wasmData()})
3. bin/build.js: Fixed build script logic that tried to read package.json before it was created

Verification

• Build completes without deprecation warnings
• All 92 tests pass (46 ristretto + 46 p256 variants)
• Example applications run without console warnings
• No breaking changes to public API

[gustavovalverde]

cc: @nikgraf (sorry for the ping, but just for visibility) :)