KSgeneral 2.1.0

New interface

• Added ks_c_cdf(n, A, B), a documented low-level interface to the Exact-KS-FFT boundary-crossing calculation. It accepts the lower (A) and upper (B) boundary vectors directly and does not use an intermediate file.

C++ source interface

• Added src/KSgeneral.h and src/KSgeneral.cpp as the source-level C++ interface. The header uses only standard C++ types and can be included by users compiling the KSgeneral numerical sources directly.
• Centralized all Rcpp::export attributes in src/KSgeneral.cpp; the numerical implementation files no longer contain Rcpp wrappers.
• Organized the numerical entry points as src/k1sample.cpp/src/k1sample.h for the one-sample implementation and src/k2sample.cpp for the two-sample KS and Kuiper implementations.

Internal changes

• Refactored the one-sample Exact-KS-FFT calculation so package functions pass boundary vectors directly to C++ instead of writing and reading Boundary_Crossing_Time.txt.
• Removed the package-internal working-directory side effect and the shared temporary-file dependency from continuous, discrete, and mixed one-sample calculations.
• Deprecated the historical file-based ks_c_cdf_Rcpp(n) interface. It is retained temporarily for backward compatibility and now issues a deprecation warning directing users to ks_c_cdf(n, A, B).