feat: add changelog grouping and supply chain hooks to goreleaser config

[nsportsman]

Summary

Improves the GoReleaser config with supply chain hooks and structured changelogs.

• Before hooks: go mod tidy -diff + go mod verify run before every release build. tidy -diff fails fast if modules are dirty (never modifies files mid-release). verify validates cached dependency checksums against go.sum.
• Changelog grouping: Release notes organized by conventional commit type (Breaking Changes, Features, Bug Fixes, Other) using the GitHub API for PR links and author handles. Scope regex supports hyphens. Breaking regex handles GoReleaser's SHA-prefixed entry format.

Incorporates 3 rounds of multi-model review feedback (Claude, Gemini, Codex).

Supersedes #70.

Test plan

• goreleaser check passes
• Verify next release produces grouped changelog

🤖 Generated with Claude Code

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: da3f4561-0f1f-4e4c-91c6-ab41d0ec72de

📥 Commits

Reviewing files that changed from the base of the PR and between 5b0c01d and 4f8da2c.

📒 Files selected for processing (1)

• .goreleaser.yaml

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Walkthrough

The .goreleaser.yaml file receives two enhancements. A pre-release before hook now validates Go module hygiene by running go mod tidy -diff and go mod verify. The changelog configuration extends to organize entries into categorized groups—Breaking Changes, Features, Bug Fixes, and Other Changes—using regex-based matching while maintaining ascending sort order.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/goreleaser-improvements-v2

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