fix: hide completion cache hint by default

[ChangeHow]

What changed

• 默认关闭 completion cache 命中提示，仅在 SUITUP_SHOW_COMPLETION_CACHE_HINT=1 时显示。
• 为工具相关模块文件补充 Generated by suitup 标记：configs/shared/tools/{_loader,atuin,bun,fzf,runtime}.zsh，确保 setup diff 检测可识别这些托管文件的行级更新。
• 新增 setup 测试：托管工具模块改动应触发 detectPendingStepUpdates 返回 zsh-config。

Validation

• npx vitest run tests/configs.test.js
• npx vitest run tests/setup.test.js

[gemini-code-assist]

Code Review

This pull request introduces a feature flag to control the visibility of the ZSH completion cache hint and adds 'Generated by suitup' headers to several tool configuration files. It also includes a new test case to verify that modifications to managed tool modules correctly trigger a pending zsh-config update. Review feedback suggests streamlining the test setup by removing unnecessary file copies and unused properties from the options object to improve focus and maintainability.

[gemini-code-assist]

测试设置中包含了拷贝多个不相关文件（aliases.zsh、plugins.zsh、prompt.zsh 和 machine.zsh）的操作，这些文件与正在测试的 zsh-config 待更新状态无关。具体来说，aliases.zsh 和 plugins.zsh 会触发它们各自独立的待更新标记，而 prompt.zsh 和 machine.zsh 并不在更新检测范围内。移除这些无关设置可以使测试更聚焦且更易于维护。

Suggested change

	for (const file of ["tools.zsh", "completion.zsh", "highlighting.zsh", "aliases.zsh", "plugins.zsh", "prompt.zsh"]) {
	copyFileSync(
	join(CONFIGS_DIR, "shared", file),
	join(completedSandbox.path, ".config", "zsh", "shared", file)
	);
	}
	for (const file of ["_loader.zsh", "fzf.zsh", "runtime.zsh", "atuin.zsh", "bun.zsh"]) {
	copyFileSync(
	join(CONFIGS_DIR, "shared", "tools", file),
	join(completedSandbox.path, ".config", "zsh", "shared", "tools", file)
	);
	}
	copyFileSync(
	join(CONFIGS_DIR, "local", "machine.zsh"),
	join(completedSandbox.path, ".config", "zsh", "local", "machine.zsh")
	);
	for (const file of ["tools.zsh", "completion.zsh", "highlighting.zsh"]) {
	copyFileSync(
	join(CONFIGS_DIR, "shared", file),
	join(completedSandbox.path, ".config", "zsh", "shared", file)
	);
	}
	for (const file of ["_loader.zsh", "fzf.zsh", "runtime.zsh", "atuin.zsh", "bun.zsh"]) {
	copyFileSync(
	join(CONFIGS_DIR, "shared", "tools", file),
	join(completedSandbox.path, ".config", "zsh", "shared", "tools", file)
	);
	}

[gemini-code-assist]

传递给 detectPendingStepUpdates 的 opts 对象包含未使用的属性 platform 和 commandExistsFn。该函数仅利用 home 属性进行路径解析。清理这些属性可以提高测试代码的清晰度。

      const opts = {
        home: completedSandbox.path,
      };