* Withhold HF_TOKEN from pull_request runs of CI workflows
The pull_request-triggered CI workflows check out and execute PR-controlled
code (install.sh, .github/scripts/**, tests/**) with secrets.HF_TOKEN in the
step environment. For a same-repo PR, GitHub provides repository secrets to the
run, so a malicious or compromised branch could modify a checked-out script to
read and exfiltrate HF_TOKEN, including by writing it into the uploaded logs/
artifact. HF_TOKEN is an external Hugging Face credential of unknown scope, so
this is the high-value exposure.
Gate every HF_TOKEN reference in these workflows with
`github.event_name != 'pull_request' && secrets.HF_TOKEN || ''`, so the real
token flows only on the trusted schedule/push/workflow_dispatch runs and PR runs
see an empty string. All model repos used by these jobs are public
(unsloth/*-GGUF), so anonymous download still works on PRs; install_llama_prebuilt.py
only sends HF auth to Hugging Face hosts and tolerates an absent token.
GITHUB_TOKEN (passed as GH_TOKEN) is intentionally left in place: it is the
auto-provisioned, job-scoped, contents:read token that expires with the job and
gives a same-repo PR author nothing they do not already have, and
install_llama_prebuilt.py needs it to authenticate the GitHub releases API or
the prebuilt llama.cpp download hits the anonymous rate-limit bucket and 403s.
* Trim the HF_TOKEN gating comments to one line per site
Comment/whitespace-only: collapse the per-step rationale to a single line and
shorten the local-agent-guides header note. No workflow logic changes (verified
each file's parsed YAML is identical before/after).