feat(commands): add version indicators and color coding to list

[CalvinAllen]

Add visual indicators to distinguish active vs inactive versions in dtvem list output.

Current State

• ✅ Basic color highlighting exists via ui.HighlightVersion()
• ✅ "(global)" text indicator shown next to global version
• ❌ No emoji indicators (🌐 for global, 📍 for local)
• ❌ No color distinction between active and inactive versions
• ❌ No local version detection in list output

Remaining Work

Emoji Indicators

• Add 🌐 emoji next to the global version
• Add 📍 emoji next to the local version (from .dtvem/runtimes.json in current directory or parent)

Color Coding

• Color code versions based on active status:
  • GREEN - Currently active version (based on current directory context)
  • WHITE/DEFAULT - Installed but not active
• Use ui.Success style (green) for active version

Local Version Support

• Query local .dtvem/runtimes.json (walk up directory tree) for local version
• Handle case where global and local are the same version (show both indicators)

Example Output

$ dtvem list node
  18.0.0
  20.0.0  🌐 (global)
  22.0.0  📍 (local)   ← GREEN (active)

Implementation Notes

• Active version follows priority: local > global > none
• Can reuse config.ResolveVersion() logic for local detection
• Location: src/cmd/list.go