feat: init 创建空配置文件，内置策略走代码默认值

tests/commands/init.test.ts

@@ -15,7 +15,7 @@ afterEach(async () => {
 });
 
 describe("runInit", () => {
-  it("创建 .rune 目录和默认 config.yaml", async () => {
+  it("创建 .rune 目录和空 config.yaml", async () => {
     await runInit(TMP_DIR, ["opencode"]);
 
     expect(existsSync(join(TMP_DIR, ".rune"))).toBe(true);
@@ -25,10 +25,7 @@ describe("runInit", () => {
       join(TMP_DIR, ".rune", "config.yaml"),
       "utf-8",
     );
-    expect(content).toContain("discuss");
-    expect(content).toContain("plan");
-    expect(content).toContain("build");
-    expect(content).toContain("archive");
+    expect(content.trim()).toBe("stages: {}");
   });
 
   it("创建 .rune/changes 和 .rune/archive 目录", async () => {