Add comment marker preview

[sedge-bot]

Summary

• add a generated SVG preview for Human++ comment marker badges
• show how legacy aliases map to punctuation markers (FIXME/BUG/XXX → !!, TODO/HACK → ??, NOTE/NB → >>)
• link the preview from the README Human Intent Markers section

Closes #2

Verification

• python3 -m py_compile tools/build.py
• python3 XML/readme smoke for site/assets/comment-marker-preview.svg
• python3 tools/build.py
• git diff --check

[sedge-bot]

Sedge re-verified and tightened this PR after noticing the generated preview did not actually show the XXX alias or an explicit >> example yet.

Update pushed: fa401e3 (docs: complete comment marker preview coverage)

Verification at fa401e3:

• python3 -m py_compile tools/build.py tools/lib/*.py
• SVG/XML structural smoke: site/assets/comment-marker-preview.svg parses and contains FIXME, BUG, XXX, TODO, HACK, NOTE, NB, !!, ??, and escaped >> labels
• README smoke confirms the documented marker families are still present
• python3 tools/build.py
• git diff --check github/main..HEAD

GitHub still reports the PR as OPEN / MERGEABLE / UNSTABLE with no surfaced checks in statusCheckRollup, so I do not see a local artifact or diff-scope blocker.

[sedge-bot]

Sedge heartbeat re-verified this PR at fa401e3.

Local checks run:

• npm install --prefix packages/vscode-extension (installed verifier deps locally; no vulnerabilities)
• npm run compile --prefix packages/vscode-extension
• python3 -m py_compile tools/build.py tools/lib/*.py
• python3 tools/build.py
• README/comment-marker artifact smoke: README.md contains the Human Intent Markers section plus !!/XXX/>>, and site/assets/comment-marker-preview.svg contains both XXX and escaped >> marker examples
• git diff --check github/main..HEAD

GitHub still reports this PR as OPEN / MERGEABLE / UNSTABLE, with no status checks surfaced in the rollup. The local clone is clean after removing verifier-only install artifacts and restoring incidental lockfile churn.