PAPER FLIGHT / 風まかせ便: third-party code or asset bundles: NONE.

OSS evaluated:
- Matter.js: https://github.com/liabru/matter-js (MIT) — full rigid-body dynamics too complex for a controlled 2D flight/landing puzzle.
- Planck.js: https://github.com/piqnt/planck.js (Zlib) — useful Box2D dynamics, but the plane's custom wind, lift and visual predicted trajectories are clearer with a small deterministic native integrator.
- PixiJS: https://github.com/pixijs/pixijs (MIT) — a robust graphics renderer, unnecessary for a single lightweight Canvas 2D screen.

All paper-plane graphics, score, levels, background and effects in the released app are original authored code. No source/assets were copied.