[Feat] Implementation of BufferManager and KvProtocol. (#991)

## Purpose
Implement BufferManager for slot-based memory management with IndexPool,
and unify SQE packing/CQE unpacking into a single KvProtocol abstraction
with comprehensive request validation and full integration testing.

## Modifications
1. Add BufferManager with IndexPool-based slot allocation, supporting
HOST, HOST_PINNED, and ASCEND_DEVICE memory types via AscendBuffer.
2. Unify Sqe/Cqe into KvProtocol base class with PackSqe/UnpackCqe,
replacing separate SqeManager and CqeManager.
3. Add ValidateRequest to check Request fields before packing, including
bit-field overflow, alignment, key length, and batch number validation
with actual values in error messages and [[unlikely]] hints.
4. Add ProtocolManager to manage send_buffer and flag_buffer instances,
with PackRequest, UnpackResponse, and PollResponseCid interfaces.
5. Use protocol-specific max batch numbers per SSU spec: BatchStore/
BatchRetrieve=110, Delete=254, Exist=256.

## Test
BufferManagerTest (19 cases), KvProtocolPackTest (38 cases), and
ProtocolManagerTest (13 integration cases) all passed. Total: 70 tests.

Author: yumingyue624

ucm/transport/kv/asu/CMakeLists.txt

@@ -1,46 +1,50 @@
-file(GLOB ASU_TRANSPORT_SOURCES CONFIGURE_DEPENDS trans/src/*.cpp)
-add_library(asu_transport SHARED ${ASU_TRANSPORT_SOURCES})
-target_include_directories(asu_transport
-    PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/trans/include
-    PRIVATE
-        ${CMAKE_CURRENT_SOURCE_DIR}/common
-        ${CMAKE_CURRENT_SOURCE_DIR}/trans/src
-        ${UCM_ROOT_DIR}/ucm/shared/infra
-)
-target_link_libraries(asu_transport PUBLIC infra_logger pthread)
+if(RUNTIME_ENVIRONMENT STREQUAL "ascend")
+    file(GLOB ASU_TRANSPORT_SOURCES CONFIGURE_DEPENDS trans/src/*.cpp)
+    add_library(asu_transport SHARED ${ASU_TRANSPORT_SOURCES})
+    target_include_directories(asu_transport
+        PUBLIC
+            ${CMAKE_CURRENT_SOURCE_DIR}/trans/include
+        PRIVATE
+            ${CMAKE_CURRENT_SOURCE_DIR}/common
+            ${CMAKE_CURRENT_SOURCE_DIR}/trans/src
+            ${UCM_ROOT_DIR}/ucm/shared/infra
+    )
+    target_link_libraries(asu_transport PUBLIC infra_logger pthread)
 
-file(GLOB ASU_CLIENT_SOURCES CONFIGURE_DEPENDS client/src/*.cpp)
-add_library(asu_client SHARED ${ASU_CLIENT_SOURCES})
-target_include_directories(asu_client
-    PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/client/include
-)
-target_include_directories(asu_client
-    PRIVATE
-        ${CMAKE_CURRENT_SOURCE_DIR}/common
-        ${CMAKE_CURRENT_SOURCE_DIR}/client/src
-        ${UCM_ROOT_DIR}/ucm/shared/infra
-)
-target_link_libraries(asu_client PUBLIC asu_transport kv_common pthread)
+    target_link_libraries(asu_transport PUBLIC trans)
 
-if(BUILD_UNIT_TESTS)
-    target_compile_definitions(asu_transport PRIVATE ASU_BUILD_TESTS)
-    include(GoogleTest)
-    file(GLOB_RECURSE ASU_TEST_SOURCE_FILES CONFIGURE_DEPENDS test/case/*.cc)
-    file(GLOB_RECURSE ASU_CLIENT_TEST_SOURCE_FILES CONFIGURE_DEPENDS client/test/*.cpp)
-    list(APPEND ASU_TEST_SOURCE_FILES ${ASU_CLIENT_TEST_SOURCE_FILES})
-    add_executable(asu.test ${ASU_TEST_SOURCE_FILES})
-    target_compile_definitions(asu.test PRIVATE ASU_BUILD_TESTS)
-    target_include_directories(asu.test PRIVATE
-        ${CMAKE_CURRENT_SOURCE_DIR}/common
-        ${CMAKE_CURRENT_SOURCE_DIR}/client/src
-        ${CMAKE_CURRENT_SOURCE_DIR}/trans/src
-        ${UCM_ROOT_DIR}/ucm/shared/infra
+    file(GLOB ASU_CLIENT_SOURCES CONFIGURE_DEPENDS client/src/*.cpp)
+    add_library(asu_client SHARED ${ASU_CLIENT_SOURCES})
+    target_include_directories(asu_client
+        PUBLIC
+            ${CMAKE_CURRENT_SOURCE_DIR}/client/include
     )
-    target_link_libraries(asu.test PRIVATE
-        asu_client
-        gtest_main gtest
+    target_include_directories(asu_client
+        PRIVATE
+            ${CMAKE_CURRENT_SOURCE_DIR}/common
+            ${CMAKE_CURRENT_SOURCE_DIR}/client/src
+            ${UCM_ROOT_DIR}/ucm/shared/infra
     )
-    gtest_discover_tests(asu.test)
+    target_link_libraries(asu_client PUBLIC asu_transport kv_common pthread)
+
+    if(BUILD_UNIT_TESTS)
+        target_compile_definitions(asu_transport PRIVATE ASU_BUILD_TESTS)
+        include(GoogleTest)
+        file(GLOB_RECURSE ASU_TEST_SOURCE_FILES CONFIGURE_DEPENDS test/case/*.cc)
+        file(GLOB_RECURSE ASU_CLIENT_TEST_SOURCE_FILES CONFIGURE_DEPENDS client/test/*.cpp)
+        list(APPEND ASU_TEST_SOURCE_FILES ${ASU_CLIENT_TEST_SOURCE_FILES})
+        add_executable(asu.test ${ASU_TEST_SOURCE_FILES})
+        target_compile_definitions(asu.test PRIVATE ASU_BUILD_TESTS)
+        target_include_directories(asu.test PRIVATE
+            ${CMAKE_CURRENT_SOURCE_DIR}/common
+            ${CMAKE_CURRENT_SOURCE_DIR}/client/src
+            ${CMAKE_CURRENT_SOURCE_DIR}/trans/src
+            ${UCM_ROOT_DIR}/ucm/shared/infra
+        )
+        target_link_libraries(asu.test PRIVATE
+            asu_client
+            gtest_main gtest
+        )
+        gtest_discover_tests(asu.test)
+    endif()
 endif()