Add optional airline label on aircraft tags

[CrispinPZA]

Resolve each flight's airline from its callsign's ICAO prefix (e.g. BAW in BAW123) via a curated lookup table holding the ICAO code, IATA acronym, full name, and a friendly short name.

A new Show: selector in the Wi-Fi setup portal chooses None / Full Airline Name / Airline Abbreviation, persisted to NVS. When set and the callsign resolves, the airline is rendered as an extra line on the aircraft tag.

[Reid-n0rc]

Hardware & testing methodology: ESP32-C3 Super Mini (esp32-c3-devkitm-1, RISC-V, 320KB RAM), 1.28" round GC9A01 240×240 SPI display, USB-C native serial. Built with PlatformIO, espressif32@6.5.0. Connected to a real WiFi AP with live ADS-B traffic; queried the device's /api/planes endpoint via curl to confirm airline resolution populated for known callsigns.

Results: no fixes needed to this PR's own logic — required real merge work (not a bug fix) reconciling with #33's tag-line changes: both restructured the same tag-rendering function for different reasons (this PR's dynamic TagLine[] list for the optional airline line vs. #33's hardcoded fields for route/speed). I combined them into one unified tag-line list rather than picking one. Verified via the API that airline resolution populates correctly for known callsigns; I did not get a clear visual confirmation on the physical display of the airline label rendering specifically (verified via API/log output, not a screen photo) — flagging as a caveat, not a failure.