feat: add /reasoning reasoning visibility

src/auto-reply/thinking.test.ts

@@ -1,8 +1,20 @@
 import { describe, expect, it } from "vitest";
-import { normalizeThinkLevel } from "./thinking.js";
+import { normalizeReasoningLevel, normalizeThinkLevel } from "./thinking.js";
 
 describe("normalizeThinkLevel", () => {
   it("accepts mid as medium", () => {
     expect(normalizeThinkLevel("mid")).toBe("medium");
   });
 });
+
+describe("normalizeReasoningLevel", () => {
+  it("accepts on/off", () => {
+    expect(normalizeReasoningLevel("on")).toBe("on");
+    expect(normalizeReasoningLevel("off")).toBe("off");
+  });
+
+  it("accepts show/hide", () => {
+    expect(normalizeReasoningLevel("show")).toBe("on");
+    expect(normalizeReasoningLevel("hide")).toBe("off");
+  });
+});