fix(ci): re-pin panic-attack scan-and-report — optional-PAT skip (Security Scan green without VERISIMDB_PAT) (#309)

Follow-up to #307: with the argv overflow gone, Security Scan on main
still failed at the dispatch step (run 28842498410) — echidna carries no
`VERISIMDB_PAT` and the `GITHUB_TOKEN` fallback can never
`repository_dispatch` to `verisimdb-data` (curl exit 22).
hyperpolymath/panic-attack#156 makes the optional secret genuinely
optional (`::notice` + skip) and prints the HTTP status/response on real
rejections. This pins forward to its merge commit `6693e01`.

Note for owner: if the estate wants echidna's scan results flowing into
verisimdb-data again, mint/restore `VERISIMDB_PAT` (part of the
PAT-rotation backlog) — the workflow will then dispatch again
automatically.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: hyperpolymath

.github/workflows/security-scan.yml

@@ -20,6 +20,6 @@ permissions:
 
 jobs:
   scan:
-    uses: hyperpolymath/panic-attack/.github/workflows/scan-and-report.yml@906781f10c92cc05261cdb99f81dbb47d096a464 # main 2026-07-07 (dispatch payload via file, not argv)
+    uses: hyperpolymath/panic-attack/.github/workflows/scan-and-report.yml@6693e01727aefdc01cbb5ddd728e9a510128f2a2 # main 2026-07-07 (skip dispatch without VERISIMDB_PAT)
     secrets:
       VERISIMDB_PAT: ${{ secrets.VERISIMDB_PAT }}