[server utils] Add utils normalize, mutex, statemachine

[MichaelWheeley]

What does this PR do?

• add server utils
  • normalize = string to numeric conversion, JSON string to numeric conversion
  • mutex = locking/unlocking, safe value and counters for asynchronous operation
  • statemachine = basic state machine with defined named states and handlers
• includes unit tests for each component

is used where? not yet, coming soon

Type of change

utils

• Bug fix
• New feature
• Performance improvement
• Refactor / code cleanup
• Documentation
• Translation
• Map layer plugin

Checklist

• App loads without console errors
• Tested in Dark, Light, and Retro themes
• Responsive at different screen sizes (desktop + mobile)
• If touching server.js: caches have TTLs and size caps (we serve 2,000+ concurrent users)
• If adding an API route: includes caching and error handling
• If adding a panel: wired into Modern, Classic, and Dockable layouts
• No hardcoded colors — uses CSS variables (var(--accent-cyan), etc.)
• No .bak, .old, console.log debug lines, or test scripts included