ci: add link-check workflow (lychee)

[satyakwok]

Same pattern as the link-check workflow already shipped to awesome-sentrix, whitepaper, canonical-contracts, and dapp-starter. Lychee scans every markdown link on PR + push to main + weekly Monday 03:00 UTC cron. Non-blocking — mirrors the gitleaks workflow's policy.

Summary by CodeRabbit

• Chores
  • Added automated link validation for documentation to ensure all markdown URLs remain accessible.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 5460def1-d08e-4705-b0e4-2c221de2c4d2

📥 Commits

Reviewing files that changed from the base of the PR and between b76ea38 and 35e556e.

📒 Files selected for processing (1)

• .github/workflows/link-check.yml

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📝 Walkthrough

Walkthrough

This pull request introduces a new GitHub Actions workflow file that automates link validation across the repository. The workflow runs the lycheeverse/lychee-action tool to scan all markdown files for dead or broken URLs. It is triggered on pull requests, pushes to the main branch, a weekly Monday schedule, and manual dispatch. The workflow operates with read-only repository permissions and is configured to report findings without failing the workflow, allowing link issues to be surfaced while maintaining workflow success.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch ci/link-check

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