星火入卷，三程共证 · Record npm 0.3.0 release

[eric8810]

Summary

• mark 0.3.0 as published in the changelog and user guides
• document Auto, Apple/Core ML, Native WebGPU, compatibility, and measured performance
• record release/promotion runs, tarball hashes, and registry integrity

Validation

• git diff --cached --check
• public npm query: all six packages have next/latest = 0.3.0
• release manifest integrity matched the promoted registry packages

No platform build is rerun: this PR only records the already completed release.