[fghaas]

• chore: Add tests/tutor-sandbox, .eggs, and .tox to .gitignore
  No reason to track these.

• build: Make Git hooks stricter

  • Extend the pre-commit hook so that it checks for newly introduced
    trailing whitespace before running tox.

  • Add a commit-msg hook to check the commit message with gitlint, and
    abort the commit if the commit message is unsatisfactory.

• docs: Improve HACKING.md

  • Be explicit about PEP 8.
  • Change from setext to ATX headings.
  • Remove references to git --no-verify.
  • Add Markdown style guide.

• docs: Add AGENTS.md

  • Add instructions for agentic coding assistants.
  • Add submodule to contain agentic coding assistant skills.

• docs: Rewrite README.md with one-sentence-per-line style

  • Convert prose to one sentence per line outside code blocks
  • Fix setext heading style to ATX headings
  • Remove trailing whitespace
  • Add proper newline at end of file
  • Structure sections with ATX headings

  Assisted-by: opencode/qwen3.6-35b-a3b-fp8

• docs: Rewrite HACKING.md with one-sentence-per-line style

  • Convert multi-line sentences to one sentence per line
  • Fix setext heading style to ATX headings
  • Remove trailing whitespace
  • Ensure bulleted sentences end with periods

  Assisted-by: opencode/qwen3.6-35b-a3b-fp8

• docs: Rewrite CHANGELOG.md with one-sentence-per-line style

  • Split multi-sentence bullets into individual sentences per line
  • Add missing period to entry in 0.1.0
  • Split compound entries in 2.0.0 and 1.0.0 BREAKING CHANGE notes
  • Add periods to bullet entries in 0.0.1

  Assisted-by: opencode/qwen3.6-35b-a3b-fp8