release/0.13.0

[mxfactorial]

0.13.0 (2026-05-24)

breaking

• Geonum::disperse now carries the phase kx − ωt in the angle (was a sign-only blade) — disperse finally matches its docstring; the return is [1, kx − ωt], so .cos_sin() reads the wave

fixed

• Angle::boost(0.0) returns the (grade 2, t = 0) backward pole instead of NaN — the horizon limit, every ray collapsing to one null direction

added

• general relativity test series: schwarzschild_test (the bondi field — redshift, precession, horizon), einstein_test (the field equation as one local condition on that field), gravitational_wave_test (disperse on the light cone), sr_gr_collapse_test (SR/GR as one boost, the knob constant or position/time-varying)

changed

• split dimension_test.rs into pseudoscalar_test.rs (the 2^n/pseudoscalar elimination) and grade_test.rs (grades and the k→4−k duality)