docs: standardize v0.8 install snippets

[jeffhuber]

Summary

• standardize remaining v0.8 install snippets on the explicit CODE_MOWER_PYTHON pattern
• include the OSS v1 checklist in the active-doc release hygiene guard
• block the stale bare python3.12 pipx snippet from returning to active docs

Verification

• scripts/dev-python -m unittest tests.test_release_hygiene
• stale-snippet scan across README.md, docs, src, and .github
• git diff --check

[gitar-bot]

Code Review ✅ Approved

Standardizes v0.8 install snippets to use the explicit CODE_MOWER_PYTHON pattern, adds the OSS v1 checklist to the release hygiene guard, and blocks a stale bare python3.12 pipx snippet from returning to active docs. No issues found.

Options

Auto-apply is off → Gitar will not commit updates to this branch.
Display: compact → Showing less information.

Comment with these commands to change the behavior for this request:

Auto-apply	Compact
gitar auto-apply:on	gitar display:verbose

_{Was this helpful? React with 👍 / 👎 | Gitar}

[jeffhuber]

Claude audit (merge-authority lane)

Head SHA: 5a5a04cb42113e833f6998876aa769c54d7c8db7
Findings: P0=0, P1=0, P2=0, P3=1 (blocker policy: any P0/P1/P2 -> BLOCKED)

Claude Audit: PASS

Summary:

Docs-only PR standardizing the pinned pipx install snippet to resolve python3.12 via command -v instead of a bare interpreter name, matching the pattern already used elsewhere in docs/pypi-release.md and docs/install.md. The accompanying test_release_hygiene.py update correctly extends the stale-phrase and active-docs checks to cover all three touched files. No functional code changed; no security, data-loss, or contract issues found.

Findings:

• [P3] Slightly awkward inline-code phrasing -- docs/v08-release-notes.md:4
  Finding ID: claude:697dfe51f175232e879a
  The sentence splits the CODE_MOWER_PYTHON assignment and the pipx install into two separate inline code spans joined by "followed by", which reads awkwardly compared to a fenced code block used in the other two updated docs. Non-blocking style nit.