docs(plan): Phase 1 Schwarzschild implementation plan
20 tasks covering: deps, minimal window, web/Trunk/WebGPU, full-screen
Material2d pipeline, orbit camera, params resource, uniforms+mirror, ray
gen, RK4 Schwarzschild integrator, CPU physics tests, lensed starfield,
Doppler accretion disk w/ Einstein halo, egui panel, storage-buffer
planets, Flamm grid, cubemap skybox, render scale, web verification,
README. Verified against Bevy 0.19 API (group-2 material bind group,
component spawning, WgpuSettings defaults).
xfy
02368a0a74