chore: import upstream snapshot with attribution

.github/cmake/subproject-integration/CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.13)
+project(zvec_subproject_integration LANGUAGES C CXX)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+set(ZVEC_SOURCE_DIR "" CACHE PATH "Path to the zvec source tree")
+if(NOT ZVEC_SOURCE_DIR)
+  message(FATAL_ERROR "ZVEC_SOURCE_DIR is required")
+endif()
+
+add_subdirectory("${ZVEC_SOURCE_DIR}" zvec)
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
+
+add_executable(zvec_embed_db_example
+  "${ZVEC_SOURCE_DIR}/examples/c++/db/main.cc")
+target_link_libraries(zvec_embed_db_example PRIVATE zvec_shared)
+
+add_executable(zvec_embed_core_example
+  "${ZVEC_SOURCE_DIR}/examples/c++/core/main.cc")
+target_link_libraries(zvec_embed_core_example PRIVATE zvec_core_shared)
+
+add_executable(zvec_embed_ailego_example
+  "${ZVEC_SOURCE_DIR}/examples/c++/ailego/main.cc")
+target_link_libraries(zvec_embed_ailego_example PRIVATE zvec_ailego_shared)