v0.9.0

What's Changed

• Sommerfeld perf Phase 4: compiled remainder assembly by @stevenmburns in #125
• Retire TriangularSolver: batched bspline sweeps (junctions + multi-port Y included), tent-basis pins, −2900 lines by @stevenmburns in #126
• Sinusoidal refl-coef ground: fused C++ Fresnel-weighted field tensor (5.6x, kills the super-quadratic fill) by @stevenmburns in #127

Full Changelog: v0.8.0...v0.9.0