Immersive Aircraft: Controller Support

WEAPON INPUT FIX
- Fixed RB / R1 failing to fire ordinary aircraft weapons on loaders where Immersive Aircraft delegates its weapon action to Minecraft's default use binding.
- Controller Support now follows Immersive Aircraft's active binding: the real fallback key is driven when the built-in binding is unchanged, while custom Immersive Aircraft weapon bindings remain respected.
- Rockets and other aircraft weapons can now be fired with RB / R1 under the same conditions as keyboard or mouse input; a Homing Missiles target lock is not required for the controller button itself to work.
- Button press and release ownership remains protected, preventing stuck inputs or duplicate launch clicks.

PRESERVED EXPERIENCE
- Retains all 1.2.0 input safety, analog fixed-wing and rotorcraft controls, latched throttle, smooth freelook, precision taxi mode, modern HUD, and per-aircraft tuning.
- Retains the optional Homing Missiles and Camera Zoom controller shortcuts.
- Preserves the established mod IDs and `config/gamepad-immersive-aircraft.properties` settings path.