WSL path format not supported in watch mode

## Problem

When running `claude-utils` on Windows with `--watch` mode, the clipboard is set to Windows-style paths like:

```
C:\Users\name\Desktop\claude-paste.png
```

However, if you're working in a **WSL terminal**, these paths cannot be used directly. WSL requires paths in the format:

```
/mnt/c/Users/name/Desktop/claude-paste.png
```

## Environment

- OS: Windows 10/11 with WSL2
- claude-utils running on Windows side
- Terminal: WSL (Ubuntu/Debian/etc.)

## Expected Behavior

When using `claude-utils` with WSL, the clipboard path should be in WSL-compatible format (`/mnt/c/...`) so users can paste and use the path directly in WSL terminals.

## Proposed Solution

Add a `--wsl` flag to the `start` command that converts Windows paths to WSL format:

```bash
claude-utils start --watch --wsl
```

This would convert `C:\Users\...` to `/mnt/c/Users/...` before setting the clipboard.

## Related PR

#1 implements this feature.