Problem

When trying to convert standard markdown links to the combined format using markmv convert --link-style combined, the tool reports "No changes needed" even when there are standard markdown links that should be converted.

Steps to Reproduce

1. Create a markdown file with standard markdown links:

- [Backend CLAUDE.md](./backend/CLAUDE.md) - Backend-specific patterns
- [Frontend CLAUDE.md](./frontend/CLAUDE.md) - React component patterns

2. Run the conversion command:

npx markmv convert CLAUDE.md --link-style combined --verbose

Expected Behavior

The tool should convert standard markdown links [text](url) to combined format [@url](url):

- [@./backend/CLAUDE.md](./backend/CLAUDE.md) - Backend-specific patterns
- [@./frontend/CLAUDE.md](./frontend/CLAUDE.md) - React component patterns

Actual Behavior

The tool reports:

No changes needed in /path/to/CLAUDE.md
=== Conversion Summary ===
Files processed: 1
Files modified: 0
Total changes: 0

Environment

• Node.js version: 20.19.4
• markmv version: (latest from npm)
• Operating System: macOS 14.4.0

Additional Context

According to the help output, the combined format should be [@url](url), but the tool doesn't detect that standard markdown links need to be converted to this format. The conversion works correctly when done manually.

This seems like the tool might not be detecting the difference between standard markdown format and combined format, or there might be an issue with the pattern matching for the combined style conversion.