Add Z4C Shell-Patch GPU acceleration (Phase 3 complete)

Create z4c_gpu_rhs_ss.cu (reusing BSSN shell FD/chain-rule kernels):
- Uploads trKd = trK + 2*TZ to GPU so existing BSSN algebraic kernels
  compute correct Z4C physical equations without modification
- New kern_z4c_post applies TZ_rhs = alpn1 * Hcon / 2, kappa1/kappa2
  constraint damping, TZ advection (lopsided), and dissipation (kodis)
- Adds TZ/TZ_rhs to Meta struct, alloc/upload/download/free lifecycle

Add cuda_compute_rhs_z4c_ss() wrapper in Z4c_class.C matching the
Fortran f_compute_rhs_Z4c_ss signature, with #define redirection for
Step/SHStep call sites and #undef before analysis functions.

Add z4c_gpu_rhs_ss.o to ABE_CUDA_CFILES and build rule in makefile.
Add kappa1_c/kappa2_c constants to gpu_rhsSS_mem.h.

Build verified with USE_CUDA_Z4C=1 + WithShell — compiles and links
cleanly. All three Shell GPU files now coexist: bssn_gpu_rhs_ss.o
(BSSN), z4c_gpu_rhs_ss.o (Z4C), both sharing FD/chain-rule kernels.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

AMSS_NCKU_source/bssn_gpu.h

@@ -49,4 +49,8 @@ int gpu_rhs(int calledby, int mpi_rank, int *ex, double &T,
 
 int gpu_rhs_ss(RHS_SS_PARA);
 
+#define Z4C_SS_PARA int calledby, int mpi_rank, int *ex, double &T, double *crho, double *sigma, double *R, double *X, double *Y, double *Z, double *drhodx, double *drhody, double *drhodz, double *dsigmadx, double *dsigmady, double *dsigmadz, double *dRdx, double *dRdy, double *dRdz, double *drhodxx, double *drhodxy, double *drhodxz, double *drhodyy, double *drhodyz, double *drhodzz, double *dsigmadxx, double *dsigmadxy, double *dsigmadxz, double *dsigmadyy, double *dsigmadyz, double *dsigmadzz, double *dRdxx, double *dRdxy, double *dRdxz, double *dRdyy, double *dRdyz, double *dRdzz, double *chi, double *trK, double *dxx, double *gxy, double *gxz, double *dyy, double *gyz, double *dzz, double *Axx, double *Axy, double *Axz, double *Ayy, double *Ayz, double *Azz, double *Gamx, double *Gamy, double *Gamz, double *Lap, double *betax, double *betay, double *betaz, double *dtSfx, double *dtSfy, double *dtSfz, double *TZ, double *chi_rhs, double *trK_rhs, double *gxx_rhs, double *gxy_rhs, double *gxz_rhs, double *gyy_rhs, double *gyz_rhs, double *gzz_rhs, double *Axx_rhs, double *Axy_rhs, double *Axz_rhs, double *Ayy_rhs, double *Ayz_rhs, double *Azz_rhs, double *Gamx_rhs, double *Gamy_rhs, double *Gamz_rhs, double *Lap_rhs, double *betax_rhs, double *betay_rhs, double *betaz_rhs, double *dtSfx_rhs, double *dtSfy_rhs, double *dtSfz_rhs, double *TZ_rhs, double *rho, double *Sx, double *Sy, double *Sz, double *Sxx, double *Sxy, double *Sxz, double *Syy, double *Syz, double *Szz, double *Gamxxx, double *Gamxxy, double *Gamxxz, double *Gamxyy, double *Gamxyz, double *Gamxzz, double *Gamyxx, double *Gamyxy, double *Gamyxz, double *Gamyyy, double *Gamyyz, double *Gamyzz, double *Gamzxx, double *Gamzxy, double *Gamzxz, double *Gamzyy, double *Gamzyz, double *Gamzzz, double *Rxx, double *Rxy, double *Rxz, double *Ryy, double *Ryz, double *Rzz, double *ham_Res, double *movx_Res, double *movy_Res, double *movz_Res, double *Gmx_Res, double *Gmy_Res, double *Gmz_Res, int &Symmetry, int &Lev, double &eps, int &sst, int &co
+
+int gpu_rhs_z4c_ss(Z4C_SS_PARA);
+
 #endif