Custom airports and helipads

Traditional airports can keep using runways. Helipads and custom landing areas can use surfaces.

surfaces = {
    ["H1"] = { ... }
}

Optional airport metadata:

type = "airport" or "helipad"
order = 10
surfaceLabel = "Runway" or "Pad"
surfaceShortLabel = "RWY" or "PAD"
surfaceOrder = { "21", "3" }
requiresGate = true or false
taxiSystem = "LSIA"
previewMapPoint = { mapU = 0.31, mapV = 0.85 }

• order controls airport sorting.
• surfaceOrder controls runway or pad sorting.
• Only enable requiresGate when gate and taxi support exist.
• The bundled gate and taxi system is LSIA-only by default.
• previewMapPoint aligns route-preview markers manually.

Add a matching key to config/routes.lua:

["LSIA_21__PILLBOX_HELI_H1"] = {
    vec3(...),
    vec3(...)
}