Update CoC policy pages, remove reporting branch, and fix workshops accessibility headings

[surfaceowl]

Summary

• Convert /code-of-conduct/code-of-conduct-policy from a redirect record to a local landing page model.

• Add a clear CTA button linking to the canonical BAPyA Code of Conduct (https://www.bapya.org/coc).

• Removed:
  -- legacy Code of Conduct reporting guide page under /code-of-conduct/code-of-conduct-response-guide/.
  -- outdated reporting-reference copy from the main /code-of-conduct/ page.

• Kept the footer at the bottom of the viewport for the short CoC policy landing page via a page-specific body class.

• Fixed accessibility heading-order violations on /speaking/workshops/ by normalizing workshop heading levels to a semantic sequence.

Why

• CoC policy content is intentionally centralized on the BAPyA site while preserving a clear local entry point.
• Deprecated reporting-branch content and references are removed to avoid stale guidance.
• CI accessibility checks were failing due to non-sequential headings on the workshops page.

Validation

• npm run build (webpack + lektor build/prune) completed successfully.
• pytest tests/test_server.py -q passed (17 passed).
• pytest -q passed (17 passed).

Notes

• Existing warning remains from lektor/pkg_resources deprecation and is unrelated to this PR’s functional changes.