chore: replace deprecated source-map-resolve

[alexandroit]

Fixes #163

Summary

• replace deprecated source-map-resolve@0.6.0 with an npm alias to @stackline/source-map-resolve@1.0.0
• preserve the installed dependency name, existing require("source-map-resolve"), and resolveSync integration
• refresh the npm lockfile

Why

The original package is deprecated and archived, while this project still needs its synchronous source-map resolution behavior. The replacement is an independently maintained MIT-licensed fork that preserves the 0.6 public API.

Compatibility note

The replacement declares Node.js 12 or newer. This repository currently tests on Node LTS and latest and uses the built-in node --test runner, but I am calling out the declared floor because css itself does not currently define an engines field.

Validation

• npm ci
• npm test on Node 24.19.0: 154 passed, 0 failed
• npm test on Node 26.8.1: 154 passed, 0 failed
• all 6 existing source-map integration tests passed, including embedded maps and Windows paths
• npm audit --omit=dev: 0 vulnerabilities
• npm pack --dry-run

Disclosure

I maintain @stackline/source-map-resolve. It is an independent fork and is not affiliated with or endorsed by the original maintainer.