fix(build): divsufsort sources are .cpp in HDiffPatch v5

MSBuild fails hard on the stale .c paths (macOS make tolerated them).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: sunnylqm

binding.gyp

@@ -12,8 +12,8 @@
         "HDiffPatch/libHDiffPatch/HDiff/private_diff/bytes_rle.cpp",
         "HDiffPatch/libHDiffPatch/HDiff/private_diff/suffix_string.cpp",
         "HDiffPatch/libHDiffPatch/HDiff/private_diff/compress_detect.cpp",
-        "HDiffPatch/libHDiffPatch/HDiff/private_diff/libdivsufsort/divsufsort64.c",
-        "HDiffPatch/libHDiffPatch/HDiff/private_diff/libdivsufsort/divsufsort.c",
+        "HDiffPatch/libHDiffPatch/HDiff/private_diff/libdivsufsort/divsufsort64.cpp",
+        "HDiffPatch/libHDiffPatch/HDiff/private_diff/libdivsufsort/divsufsort.cpp",
         "HDiffPatch/libHDiffPatch/HDiff/private_diff/limit_mem_diff/digest_matcher.cpp",
         "HDiffPatch/libHDiffPatch/HDiff/private_diff/limit_mem_diff/stream_serialize.cpp",
         "HDiffPatch/libHDiffPatch/HDiff/private_diff/limit_mem_diff/adler_roll.c",