fix(config): accept $schema key in root config (#15280)

* fix(config): accept $schema key in root config (#14998)

* fix: strip $schema via preprocess to avoid spurious UI section

* fix(config): allow root  without zod preprocess wrapper

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/config/config.schema-key.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, it } from "vitest";
+import { OpenClawSchema } from "./zod-schema.js";
+
+describe("$schema key in config (#14998)", () => {
+  it("accepts config with $schema string", () => {
+    const result = OpenClawSchema.safeParse({
+      $schema: "https://openclaw.ai/config.json",
+    });
+    expect(result.success).toBe(true);
+    if (result.success) {
+      expect(result.data.$schema).toBe("https://openclaw.ai/config.json");
+    }
+  });
+
+  it("accepts config without $schema", () => {
+    const result = OpenClawSchema.safeParse({});
+    expect(result.success).toBe(true);
+  });
+
+  it("rejects non-string $schema", () => {
+    const result = OpenClawSchema.safeParse({ $schema: 123 });
+    expect(result.success).toBe(false);
+  });
+});