Phase insert failed when zero-padding differed between user input and
ROADMAP.md headers (e.g. "9.05" vs "09.05"). Normalize input and use
flexible regex matching with optional leading zeros.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Projects with "type": "module" in package.json cause Node to treat
gsd-tools.js as ESM, crashing on require(). The .cjs extension forces
CommonJS regardless of the host project's module configuration.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>