Create a complete, compilable Flutter project for a Flappy Bird clone. Use native Flutter widgets and minimize external libraries.
Gameplay:
Tap to flap wings
Bird falls due to gravity
Pipes spawn at intervals, scroll left
Collision with pipes or ground ends game
Score points for passing pipes
Graphics (in-code definitions preferred, or provide necessary image assets):
Pixelated bird (flapping animation)
Green pipes
Daytime sky background
Ground texture
Nice-to-haves: background music, flap/score/crash sounds.