重构：将项目资源目录从 .opencode 迁移到 .Aether

[Spin-Particle]

Issue for this PR

Closes #3

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

本次改动将项目级资源目录从 .opencode 迁移为 .Aether，同时保留对旧目录 .opencode 的兼容读取，以尽量降低行为变化和升级风险。

主要改动包括：

• 运行时配置目录查找支持 .Aether 和 .opencode
• 默认项目级写入路径切换到 .Aether
• CLI 与桌面端打包资源输入改为 .Aether
• 更新与项目资源目录相关的少量提示文案
• 增加针对 .Aether 默认路径和 .opencode 兼容路径的测试

兼容策略如下：

• 读取：优先 .Aether，兼容 .opencode
• 写入：默认写入 .Aether
• 打包：从 .Aether 读取默认资源
• 暂不修改全局安装路径、数据库路径、环境变量与包命名

How did you verify your code works?

我在本地完成了以下验证：

• packages/opencode 类型检查通过
• 重点测试通过：
  • test/config/config.test.ts
  • test/config/tui.test.ts
  • test/agent/agent.test.ts
  • test/file/ripgrep.test.ts

另外，push 时 pre-push hook 自动执行了 bun turbo typecheck，结果通过。

Screenshots / recordings

本次改动不涉及新的界面布局或视觉改动，暂无截图。

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

Hey! Your PR title 重构：将项目资源目录从 .opencode 迁移到 .Aether doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, core).

See CONTRIBUTING.md for details.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍