feat: init 创建空配置文件，内置策略走代码默认值

src/commands/init.ts

@@ -1,8 +1,6 @@
 import { existsSync } from "node:fs";
 import { mkdir, writeFile } from "node:fs/promises";
 import { join } from "node:path";
-import { stringify as stringifyYaml } from "yaml";
-import { defaultConfig } from "../defaults/config.ts";
 import { CHANGES_DIR, ARCHIVE_DIR, RUNE_DIR, CONFIG_FILE } from "../types.ts";
 import { injectOpenCode } from "../adapters/opencode.ts";
 import { injectClaudeCode } from "../adapters/claude-code.ts";
@@ -29,8 +27,7 @@ export async function runInit(
 
   const configPath = join(runeDir, CONFIG_FILE);
   if (!existsSync(configPath)) {
-    const yaml = stringifyYaml(defaultConfig);
-    await writeFile(configPath, yaml, "utf-8");
+    await writeFile(configPath, "stages: {}\n", "utf-8");
   }
 
   for (const tool of tools) {