合并 chb-replace：C++ 算子替换 Fortran bssn_rhs，添加回退开关与独立 PGO profdata

- 合并 chb-replace 分支，引入 bssn_rhs_c.C / fderivs_c.C / fdderivs_c.C /
  kodiss_c.C / lopsided_c.C 五个 C++ 算子实现
- 添加 USE_CXX_KERNELS 开关（默认 1），设为 0 可回退到原始 Fortran bssn_rhs.o
- TwoPunctureABE 改用独立的 TwoPunctureABE.profdata 而非 default.profdata

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AMSS_NCKU_source/makefile.inc

@@ -8,12 +8,17 @@ filein  = -I/usr/include/ -I${MKLROOT}/include
 
 ## Using sequential MKL (OpenMP disabled for better single-threaded performance)
 ## Added -lifcore for Intel Fortran runtime and -limf for Intel math library
-LDLIBS  = -L${MKLROOT}/lib -lmkl_intel_lp64 -lmkl_sequential -lmkl_core -lifcore -limf -lpthread -lm -ldl
+LDLIBS  = -L${MKLROOT}/lib -lmkl_intel_lp64 -lmkl_sequential -lmkl_core -lifcore -limf -lpthread -lm -ldl -liomp5
 
 ## PGO build mode switch (ABE only; TwoPunctureABE always uses opt flags)
 ##   opt        : (default) maximum performance with PGO profile-guided optimization
 ##   instrument : PGO Phase 1 instrumentation to collect fresh profile data
 PGO_MODE ?= opt
+
+## Kernel implementation switch
+##   1 (default) : use C++ rewrite of bssn_rhs and helper kernels (faster)
+##   0           : fall back to original Fortran kernels
+USE_CXX_KERNELS ?= 1
 f90          = ifx
 f77          = ifx
 CXX          = icpx