Verify each finding against the current code and only fix it if needed.

Inline comments:
In @.github/workflows/verify.yml:
- Around line 6-9: The workflow-level env block is missing PREK_HOME which
causes every reference to ${{ env.PREK_HOME }} to be empty; add a PREK_HOME
entry to the same env block (near CACHE_VERSION, DEFAULT_PYTHON, VENV) with the
correct path for the prek cache directory (e.g., set PREK_HOME:
/path/to/prek/cache or the CI-appropriate path), so reusable actions and caches
that reference ${{ env.PREK_HOME }} receive a valid value.

---

Outside diff comments:
In @.github/workflows/verify.yml:
- Around line 114-124: The "Lint markdown files" job uses pre-commit directly
while the "pylint" job uses prek; update the Lint markdown files step to run the
pymarkdown hook via prek for consistency: replace the `pre-commit run
--show-diff-on-failure --color=always --all-files --hook-stage manual
pymarkdown` invocation in the "Lint markdown files" step with the equivalent
`prek run --show-diff-on-failure --color=always --all-files --hook-stage manual
pymarkdown` so both hooks use prek (matching the pylint step).

---

Nitpick comments:
In @.github/workflows/merge.yml:
- Around line 6-8: The env variable CACHE_VERSION in merge.yml is inconsistent
with verify.yml and appears unused; either remove CACHE_VERSION from the env
block or set it to the same value used in verify.yml (e.g., change CACHE_VERSION
to 2) to maintain consistency; ensure you only modify the env entry named
CACHE_VERSION (leave DEFAULT_PYTHON untouched) and, if keeping CACHE_VERSION,
search other workflows for references to confirm the chosen value is correct.