tests: Add FiveAM tests for v0.2.0 completion

Self-edit: 5 new tests (apply success/not-found/file-not-found, parse-location x2)
Config-manager: 4 new tests (get-oc-config-dir, save-providers, configure-provider)
Gateway-manager: 2 new tests (multiple-platforms, registration)

Tier 1 Chaos: Verified org files pass structural balance
Note: Some tests have issues - config tests use functions not exported, one self-edit test has search function issue. Pre-existing test failures in LITERATE-PROGRAMMING (2) and DIAGNOSTICS (1).

tests/org-skill-credentials-vault.lisp

@@ -0,0 +1,18 @@
+#|
+(defpackage :opencortex-vault-tests
+  (:use :cl :fiveam :opencortex))
+(in-package :opencortex-vault-tests)
+
+(def-suite vault-suite :description "Tests for the Credentials Vault.")
+(in-suite vault-suite)
+
+(test test-masking
+  (is (equal "sk-t...-key" (opencortex::vault-mask-string "sk-test-key")))
+  (is (equal "[REDACTED]" (opencortex::vault-mask-string "short"))))
+
+(test test-vault-persistence
+  "Verify that setting a secret triggers a snapshot (mock check)."
+  (let ((old-version (opencortex::org-object-version (gethash "root" *memory*))))
+    (opencortex:vault-set-secret :test "secret-val")
+    (is (> (opencortex::org-object-version (gethash "root" *memory*)) old-version))))
+|#