ref(upstream): FULL TREE — Deep-Spark xllm (1470) + ds_vllm csrc/models (703)

Replaces cherry-picked upstream_ref with complete source trees.

xllm/ — Iluvatar official C++ inference engine (15MB, 1470 files)
  Complete: kernels → layers → models → runtime → scheduler → api
  Excluded: .git, binary images, third_party submodule checkouts

ds_vllm/ — Iluvatar official vllm fork (8MB, 703 files)
  Included: csrc/ (ALL CUDA kernels), fused_moe/, qwen3_5 model, _custom_ops
  Excluded: tests, benchmarks, docs, examples (not needed for reference)

Critical call chains now fully traceable:
  MoE: moe_topk_softmax_kernels.cuh → ixformer.h → fused_moe.cpp → layer
  GDN: qwen3_gated_delta_net_base.cpp → qwen3_5_gated_delta_net.cpp
  Attention: ixformer.h → xllm_paged_attention → attention.cpp

upstream_ref/xllm/cmake/proto_library.cmake

@@ -0,0 +1,69 @@
+include(CMakeParseArguments)
+include(CMakePrintHelpers)
+
+# inspired by https://github.com/abseil/abseil-cpp
+# proto_library()
+# CMake function to imitate Bazel's proto_library rule.
+#
+# Parameters:
+# NAME: name of target
+# SRCS: List of proto source files for the library
+# DEPS: List of other libraries to be linked in to the binary targets
+# COPTS: List of private compile options
+# DEFINES: List of public defines
+# LINKOPTS: List of link options
+#
+# cc_library(
+#   NAME
+#     awesome
+#   HDRS
+#     "a.h"
+#   SRCS
+#     "a.cc"
+# )
+# proto_library(
+#   NAME
+#     proto_lib
+#   SRCS
+#     "b.proto"
+#   DEPS
+#     :awesome
+# )
+#
+function(proto_library)
+  # parse arguments and set variables
+  cmake_parse_arguments(
+    PROTO_LIB # prefix
+    "" # options
+    "NAME" # one value args
+    "SRCS;COPTS;DEFINES;LINKOPTS;DEPS" # multi value args
+    ${ARGN}
+  )
+  # generate cpp and hpp files from proto files using protoc compiler
+  protobuf_generate_cpp(PROTO_SRCS PROTO_HDRS ${PROTO_LIB_SRCS})
+
+  add_library(${PROTO_LIB_NAME} STATIC)
+  target_sources(${PROTO_LIB_NAME}
+    PRIVATE ${PROTO_SRCS} ${PROTO_HDRS}
+  )
+
+  target_link_libraries(${PROTO_LIB_NAME}
+    PUBLIC protobuf::libprotobuf
+  )
+  target_include_directories(${PROTO_LIB_NAME}
+    PUBLIC 
+      ${Protobuf_INCLUDE_DIRS}
+      ${CMAKE_CURRENT_BINARY_DIR}
+  )
+  target_compile_options(${PROTO_LIB_NAME} 
+    PRIVATE 
+      ${PROTO_LIB_COPTS}
+      -Wno-unused-parameter
+  )
+  target_compile_definitions(${PROTO_LIB_NAME} 
+    PUBLIC 
+      ${PROTO_LIB_DEFINES}
+  )
+
+  add_library(proto::${PROTO_LIB_NAME} ALIAS ${PROTO_LIB_NAME})
+endfunction()