feat: add comprehensive onboarding system with profile-aware service …

[zechtz]

…discovery

• Create 3-step onboarding wizard for new users:

  1. Profile creation with active profile support
  2. Auto-discovery using profile directories
  3. Service configuration with drag-and-drop ordering

• Add profile active state management:

  • Add isActive field to CreateProfileRequest (frontend/backend)
  • Implement clearActiveProfiles logic in profile service
  • Auto-set first profile as active during onboarding

• Enhance auto-discovery integration:

  • Update OnboardingDiscoveryStep to use scanForServices from AutoDiscoveryModal
  • Remove manual directory input - use profile-aware backend scanning
  • Fix API endpoints to match backend handlers

• Improve configuration management:

  • Replace custom ordering UI with ConfigurationManager's drag-and-drop interface
  • Use react-beautiful-dnd for smooth service reordering
  • Create and apply configuration automatically after onboarding
  • Ensure service startup order is immediately functional

• Add onboarding state management:

  • Create useOnboarding hook for first-time user detection
  • Integrate with AuthenticatedApp for automatic triggering
  • Add manual onboarding access via GlobalConfigModal