[keys-i]

Summary

• highlight file previews with the Rich/Pygments stack already installed by Textual
• detect every bundled lexer by filename and content, including extensionless repository scripts
• retain line numbers, keyboard scrolling, bounded reads, and plain-text fallback

Scope

• bin/
• dev/
• lib/
• sys/
• Documentation or repository settings

Testing

Commands run:

uvx ruff@0.16.0 format --check --target-version=py311 ...
uvx ruff@0.16.0 check --target-version=py311 ...
PYTHONDONTWRITEBYTECODE=1 uv run dev/gui.py --root . --self-test  # 3 consecutive passes
sh -n sys/linux/clean && bash sys/linux/clean --self-test
zsh -n sys/macos/clean && zsh sys/macos/clean --self-test
bash run.sh --self-test
bash -s -- --self-test < run.sh
uv run --script bin/... --self-test
uv audit --script ...
uvx bandit@1.9.4 --quiet --severity-level medium ...
npx --yes prettier@3.9.6 --check ...

All local checks passed on macOS with uv-selected Python 3.14. Pygments 2.20 exposes 598 bundled lexers, 597 aliases, and 839 filename patterns. Final-head Linux shellcheck, Windows PowerShell, CodeQL, and OSV remain CI gates.

Checklist

• The change is focused and contains no unrelated files.
• The code is clean and comments explain intent or risk.
• New or changed behaviour has a repeatable test or documented manual check.
• Help text and dependencies are current.
• Destructive behaviour and elevated permissions are clearly disclosed.
• No credentials, private data, or machine-specific paths are included.

Reviewer Notes

No dependency was added. File reads remain repository-confined, symlink-rejecting, regular-file-only, and capped at 256 KiB. Unknown formats fall back to plain text. The commit is unsigned by explicit user instruction after the configured signing key was unavailable.

The fixed-model gatekeeper was unavailable for this ChatGPT account. The contract-authorized gpt-5.6-sol ultra fallback reviewed the corrected final diff and returned VERDICT: PASS. Rollback is a revert of commit 3bda102.