claude.yml: trim the multi-line WORKFLOW_TOKEN comment block

[d-morrison]

Follow-up from PR #11 review (raised twice, never applied).

Problem

The WORKFLOW_TOKEN secret in .github/workflows/claude.yml has an 8-line explanatory comment block:

# .github/workflows/claude.yml:161-168
      # Token used for the git pushes (branches / commits). The integrated
      # GITHUB_TOKEN cannot push commits that create or update files under
      # `.github/workflows/` — GitHub rejects that without the `workflows`
      # scope, which GITHUB_TOKEN never has. Set this to a PAT or GitHub App
      # token with `contents:write` + `workflows:write` in repos where Claude
      # edits workflow files (e.g. this repo dogfooding itself). When unset,
      # pushes fall back to GITHUB_TOKEN, which is fine for repos that never
      # touch `.github/workflows/`.
      WORKFLOW_TOKEN:
        required: false

The PR #11 reviewer flagged this twice against CLAUDE.md / the SERG lab manual's comment-conciseness guidance.

Proposed fix

Condense to a one/two-line comment, optionally moving the longer rationale into the README's WORKFLOW_TOKEN documentation (which already covers this), so the workflow file stays terse.

Trivial style cleanup — lowest priority of the batch.