Add comparator API descriptor and libcomparatorCore scaffold.

Introduce ExportedComparatorTypeDesc/ComparatorLibDesc with inline
sanity checks, and add a core comparator shlib exporting three stub types.

Co-authored-by: Cursor <cursoragent@cursor.com>

CMakeLists.txt

@@ -196,6 +196,7 @@ add_subdirectory(libspinscale)
 # Add core components
 add_subdirectory(smocore)
 add_subdirectory(commonLibs)
+add_subdirectory(comparatorLibs)
 add_subdirectory(stimBuffApis)
 add_subdirectory(wilzorApis)
 add_subdirectory(devices)