Clean up unused components and legacy files

- Remove DashboardWeeklyTopRefactored.tsx (unused refactored version)
- Remove DashboardSoftSkillsLeaderboard.tsx (replaced by new leaderboard system)
- Remove ClientAddModalOld.tsx (legacy modal version)
- Remove TestModal.tsx (temporary test component)

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

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Zeff01