fix(ci): run adversarial audit on Dependabot PRs

[Conrad Rockenhaus (skyphusion)]

Summary

• Drop the Dependabot author skip on the adversarial audit workflow.
• Dependabot-triggered runs use org Dependabot secrets (same names as Actions secrets).
• PR comment step is continue-on-error (Dependabot GITHUB_TOKEN is read-only; artifact remains).

Template + runbook: skyphusion-labs/fleet-chezmoi#1520

Test plan

• After merge, update an open Dependabot PR onto main
• Confirm Adversarial audit runs and does not skip

[github-actions]

Adversarial security audit

Generated 2026-08-05T10:22:21.071Z · 520a906...057f887

GitHub Workflow audit: removing Dependabot skip and adding continue-on-error exposes token misuse and silent failures; otherwise trust model is documented.

Severity	Location	Finding
high	.github/workflows/adversarial-audit.yml:77	Dependabot PRs now run untrusted code with org secrets: Dependabot is no longer skipped. A malicious dependency update (package bump) can exfiltrate ADVERSARIAL_AUDIT_CF_API_TOKEN/CF_AIG_TOKEN during install/build.
medium	.github/workflows/adversarial-audit.yml:147	continue-on-error masks PR comment failure: Adding continue-on-error: true to the PR comment step means a compromised GH_TOKEN or posting error will not fail the job.
medium	.github/workflows/adversarial-audit.yml:75	PR branch controls workflow and token exposure: Known residual: on pull_request trigger, the workflow copy on the PR branch runs, so any write-access identity can rewrite steps to steal tokens.
low	.github/workflows/adversarial-audit.yml:91	AUDIT_SCRIPTS_PIN is a single global substitution point: One variable controls the checkout ref and the verification expectation. A malicious bump to this variable bypasses both checks simultaneously.
info	.github/workflows/adversarial-audit.yml:80	Org Dependabot secrets have visibility=all: Comment states Dependabot secrets are seeded with visibility=all. This broadens token exposure to every Dependabot-originated workflow in the org.