Wave 3 performance pass across diffusion, hodge, spectral, and DEC (#19)

* perf(diffgeo): add wave3 harness and reuse form operators

* perf(diffgeo): densify weak derivative assembly

* perf(spectral): reuse circular coordinate setup

* perf(diffgeo): parallelize form up-laplacian assembly

* docs(perf): record wave3 rejected experiments

* docs(perf): summarize wave3 campaign state

* perf(spectral): cache normalized kernel operator

* perf(diffusion): fuse post-knn build passes

* perf(hodge): cache gamma assembly in workspace

* docs(perf): update wave3 report

* perf(dec): parallelize stable face-incidence build

* docs(perf): record wave3 dec pass and rejected trials

* perf(circular): matrixize workspace preparation

* docs(perf): record circular prep rewrite

* perf(spectral): loosen tolerance for small basis solves

* docs(perf): record spectral tolerance pass

* perf(hodge): matrixize curl energy assembly

* docs(perf): record hodge curl matrix pass

* perf(spectral): use cholesky whitening for dense solves

* docs(perf): record dense solve pass

* docs(perf): record diffgeo mixed gamma rejection

* style: apply clang-format to wave3 perf changes

Author: Autoparallel

CMakeLists.txt

@@ -98,6 +98,9 @@ target_link_libraries(bench_dod PRIVATE igneous benchmark::benchmark)
 add_executable(bench_pipelines benches/bench_pipelines.cpp)
 target_link_libraries(bench_pipelines PRIVATE igneous benchmark::benchmark)
 
+add_executable(bench_diffgeo benches/bench_diffgeo.cpp)
+target_link_libraries(bench_diffgeo PRIVATE igneous benchmark::benchmark)
+
 add_executable(igneous-mesh src/main_mesh.cpp)
 target_link_libraries(igneous-mesh PRIVATE igneous fmt::fmt)