[Feature Request] Add automatic .env file protection to prevent accidental secret exposure in tool execution

**Bug Description**
The problem is that .env files are very commonly used in each projects and claude comes with setup that allows to read all secret keys form it. The security is put on user shoulders which creates huge human factor in terms of lack of security. There is PreToolUse hook that could be used to block but it have to be done by user manually leavig room of unsecurity for secrets huge

**Environment Info**
- Platform: darwin
- Terminal: WarpTerminal
- Version: 2.1.263
- Feedback ID: 7437f4f9-e7c8-4bad-a403-7620841ab465

**Errors**
```json
[]
```

Start by locating the existing PreToolUse hook and the tool-execution path that can read project files; the issue names no specific file or test. Define the protection behavior for .env files and its validation cases before implementing, then verify that tool execution cannot expose their contents by default.

由索引模型根据 Issue 内容生成。