chore(repo): Add agents file alongside a few skills

[vmarcella]

Summary

This branch adds repository-level Codex guidance and repo-local authoring
skills. The final outcome is an AGENTS.md file for always-on repository
policy, a Codex environment file, and two dedicated skills that handle
long-lived documentation and tutorial authoring workflows.

Related Issues

None linked.

Changes

• Added AGENTS.md with repository guidance for structure, architecture,
  coding practices, testing, pull requests, and documentation requirements.
• Added .codex/environments/environment.toml to define the workspace setup
  script for Codex.
• Added the long-lived-docs-authoring skill and its agents/openai.yaml
  metadata for specs, plans, guides, and other durable Markdown docs.
• Added the tutorial-authoring skill and its agents/openai.yaml metadata
  for step-by-step tutorials in docs/tutorials/.
• Kept the final AGENTS.md focused on repo-wide policy while pointing
  documentation-heavy workflows at the new skills.

Type of Change

• Feature (non-breaking change that adds functionality)
• Documentation (updates to docs, specs, tutorials, or comments)
• Bug fix (non-breaking change that fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactor (code change that neither fixes a bug nor adds a feature)
• Performance (change that improves performance)
• Test (adding or updating tests)
• Build/CI (changes to build process or CI configuration)

Affected Crates

• lambda-rs
• lambda-rs-platform
• lambda-rs-args
• lambda-rs-logging
• Other: repository tooling / Codex workspace metadata

Checklist

• Code follows the repository style guidelines (cargo +nightly fmt --all)
• Code passes clippy (cargo clippy --workspace --all-targets -- -D warnings)
• Tests pass (cargo test --workspace)
• New code includes appropriate documentation
• Public API changes are documented
• Breaking changes are noted in this PR description

Testing

Manual verification steps (if applicable):

N/A

Screenshots/Recordings

Not applicable.

Platform Testing

• macOS
• Windows
• Linux

Additional Notes

• This branch changes repository guidance and Codex-specific tooling only.
• No Rust crates or public APIs are modified.

[github-actions]

✅ Coverage Report

📊 View Full HTML Report (download artifact)

Overall Coverage

Metric	Value
Total Line Coverage	74.26%
Lines Covered	13663 / 18399

No Rust files changed in this PR.

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Generated by cargo-llvm-cov · Latest main coverage

_{Last updated: 2026-03-22 23:31:46 UTC · Commit: 943298d}

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