Harden doctor and changelog output

[axadrn]

Summary

This closes the remaining Phase 4 CLI robustness work.

What changed

• Parse commented Go module directives and real Go and Git version formats.
• Skip the Go version gate when a project has no Go directive.
• Report optional Task, Tailwind, and Docker tooling as warnings.
• Use platform-neutral environment setup advice and bound .env reads.
• Label prereleases and state the ten-release changelog limit.
• Show GitHub rate-limit reset times.
• Remove terminal control characters from release bodies.

Verification

• Full test suite with Race Detector.
• Repeated focused doctor, changelog, and release-client race tests.
• Vet, build, module tidiness, diff, prose, and branding checks.