[feature / bugFix / lang] fix satellite speed calc, add languages

[MichaelWheeley]

What does this PR do?

• use allUnits.dist to display metric or US units (and not both)
• correct metric speed calculation, there was an incorrect factor of 0.539957 in the km/h display that is removed
• corrected (removed_ units of 'Downlink', 'Uplink' and 'Tone' which previously was displaying duplicate units. The units originate as part of the text coming from satellite.js
• create language keys for wording where needed, copy to all language JSONs using en as master (needs native language speakers to update)
• updated th language

Type of change

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

How to test

1. enable satellite layer
2. select other language

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)

[MichaelWheeley]

the current staging code (i.e. prior to this PR) generates this screen shot
the speed "14,889 kn/h" is incorrect, whereas the 17,134 mph is reasonable for a satellite in orbit