Compact onboarding file capturing hard-won, non-obvious repo facts:
- Dual-target build (desktop + web/WebGPU) and the wasm-only
web_sys_unstable_apis rustflag (.cargo/config.toml) that is a no-op
on desktop — easy to break during cleanup.
- Always run --release for visual checks; the debug ray tracer is too
slow and will look broken.
- The CPU<->shader mirror in src/physics.rs: it is a hand-maintained
duplicate of black_hole.wgsl kept solely so the capture/escape
boundary is testable. Editing one side without the other makes tests
pass on code the shader contradicts.
- The three Bevy 0.19 gotchas that cause the recurring grey screen
(nudge_camera for issue #24448, EguiPrimaryContextPass placement,
real storage buffer asset instead of default handle) — exactly what
this branch's recent commits fix.
- Reserved-but-intentionally-unwired fields (render_scale, spin) and
the Rs=1 natural-units convention so an agent does not 'fix'
intentional dead code or invent unit conversions.
- Git workflow: self-judge whether to commit, granular detailed
commits, never push.
No code changes.
