Plane Radar 0.1.3: usability and readability polish

[devnulluk]

What changed

• fixes Keepdexpansion Enter submission for callsigns and Radar Options
• adds a keyboard-Down visible-aircraft chooser with callsign and route
• enlarges and strengthens Flight Follow text for the round LCD
• keeps the splash visible for about five seconds
• defaults the enabled LED radar sweep to 25% and adds 25/50/75/100% controls
• reduces idle-sweep jumps after blocking network polls
• makes aircraft trails approximately 50% less faded
• packages the app as version 0.1.3

Why

The 0.1.2 hardware trial exposed several tiny-screen readability and keyboard-event issues. This iteration makes the most-used follow and selection paths legible and dependable without changing the universal F/Back control or the physical Down location refresh.

Validation

• python -m unittest discover -s tests -v — 55 tests passed
• Python syntax compilation passed
• diff validation passed
• simulator visual checks passed for Radar Options, visible-aircraft chooser, focused radar and flight details
• simulator input assertions passed for Enter submission, Enter option selection and keyboard-Down chooser opening