test(ci): verify echidna-validation + codeql fixes for PR #133

TEST COMMIT - Triggers:
- echidna-validation: Should install provers and pass
- codeql: Should complete in <60 min (not hang)
- hypatia-scan: Should use new SHA with timeout

Expected: All green, no 'waiting on results', no prover errors.
Delete this commit after CI passes.

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

Author: hyperpolymath

.github/TEST_CI_ECHIDNA.md

@@ -0,0 +1,10 @@
+# CI TEST: ECHIDNA validation + CodeQL for valence-shell PR #133
+# SPDX-License-Identifier: MPL-2.0
+# Copyright (c) Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
+
+Test commit to verify PR #133 fixes:
+- echidna-validation.yml: prover installation
+- codeql.yml: 60 min timeout
+- hypatia-scan.yml: new SHA
+
+DELETE AFTER VERIFICATION.