build: add cmake install rules for libcuframes

cmake --install теперь правильно кладёт libcuframes.so/.a в lib/ и
headers в include/cuframes/. Нужно для downstream builders (FFmpeg
patched build, deb packaging).

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

libcuframes/CMakeLists.txt

@@ -58,6 +58,20 @@ foreach(target cuframes cuframes_static)
     )
 endforeach()
 
+# Install rules — нужны для downstream проектов которые используют cmake --install
+# (FFmpeg-cuframes Dockerfile builders, deb-пакетирование).
+include(GNUInstallDirs)
+install(TARGETS cuframes cuframes_static
+    EXPORT cuframesTargets
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+)
+install(DIRECTORY ${CMAKE_SOURCE_DIR}/include/cuframes
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+    FILES_MATCHING PATTERN "*.h" PATTERN "*.hpp"
+)
+
 # Tests
 if(BUILD_TESTING)
     add_subdirectory(tests)