recorder: default OB_SDK_LIB_NAME to OrbbecSDK for SDK v2.4.3

The example CMakeLists expected OB_SDK_LIB_NAME, which SDK v2.8.6 sets in the
example scope but v2.4.3 (JetPack 6) does not — leaving a link to bare "ob::"
that fails at generate time. The stock examples link ob::OrbbecSDK, so default
to that when unset. Keeps the Nano's build working.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

recorder/CMakeLists.txt

@@ -52,6 +52,13 @@ if(WIN32)
     set(K4ARECORD_LIB    "${K4A_WRAPPER_DIR}/${K4A_WRAPPER_BUILD_SUBDIR}/bin/k4arecord.lib")
 endif()
 
+# The SDK's library-target name. v2.8.6 (the Nano) sets OB_SDK_LIB_NAME in the
+# example scope; v2.4.3 (JetPack 6 Orin) does not, leaving "ob::" — a CMake error.
+# The stock examples link ob::OrbbecSDK, so default to that when it is unset.
+if(NOT OB_SDK_LIB_NAME)
+    set(OB_SDK_LIB_NAME OrbbecSDK)
+endif()
+
 target_link_libraries(${PROJECT_NAME}
     ob::${OB_SDK_LIB_NAME}
     ob::examples::utils