feat: auto-install Maven when WORK_MACHINE=true

## Summary
Add Maven to the automatic installation when `WORK_MACHINE=true` is set.

## Context
During development work on a Java Spring Boot project, Maven was needed but not available locally. Had to manually install via `brew install maven`.

## Proposed Solution
Add Maven installation to the work machine setup in `setup.sh` or appropriate installer script.

## Implementation Notes
- Should be installed when `WORK_MACHINE=true`
- Use `brew install maven` on macOS
- Consider adding to existing Java/development tools section if one exists

## Related Work
This came up while working on travel-hosp-backend project where Maven was required for local development but not available by default.

🤖 Generated with [Claude Code](https://claude.ai/code)

Start by locating setup.sh or the appropriate installer script and inspect the existing Java or development-tools section. Verify how WORK_MACHINE=true controls installation and how macOS Homebrew packages are handled. Done means the work-machine setup installs Maven with brew install maven on macOS.

Written by the indexing model from the issue text.