[Feature] Satellite range / range rate / doppler factor, with languages

[MichaelWheeley]

What does this PR do?

When satellite is above horizon calculates and displays range / range rate / doppler factor in US or metric units.
Language keys for new words created using 'en' as master, needs non-AI native speakers to update
Language en, th are complete.
Added brief explanation of doppler factor into documentation.

Type of change

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

How to test

1. only works when satellite is above horizon (I modified DE location to make it quicker)
2. change units between US and metric
3. change languages, en and th are complete

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

Screenshots (if visual change)

• Satellite below horizon:

• Satellite above horizon, metric units:

• Satellite above horizon, US units:

• Satellite above horizon, metric units, th language: