fix(test): use valid JSON Schema in workflow-resolution test fixture

The test used a fake CasRef string as frontmatter, which fails
putSchema validation when loading from YAML files. Replace with
a proper JSON Schema object.

Fixes pre-existing failures in workflow-resolution, cas-exit-code,
and thread-step-count tests.

packages/cli-workflow/src/__tests__/workflow-resolution.test.ts

@@ -31,7 +31,13 @@ function makeMinimalPayload(name: string, description: string): WorkflowPayload
         capabilities: [],
         procedure: "",
         output: "",
-        frontmatter: { type: "0000000000000" } as unknown as CasRef,
+        frontmatter: {
+          type: "object",
+          properties: {
+            $status: { type: "string" },
+          },
+          required: ["$status"],
+        } as unknown as CasRef,
       },
     },
     graph: {