fix(build): bridge编译不依赖torch.utils.cpp_extension

corex torch精简了cpp_extension模块，改用手动发现torch include/lib路径。
同时确认Tier1 (ixformer.functions) 已在真机验证通过：
- silu_and_mul ✓
- rms_norm ✓
- moe_topk_softmax ✓
即使bridge编不出来，ix_unified也通过Tier1走ixformer硬件加速。

ex_engine/build_unified_bridge.sh

@@ -1,16 +1,6 @@
 #!/usr/bin/env bash
-# build_unified_bridge.sh — Compile ix_unified_bridge.so on BI-V100 real hardware
-#
-# This builds a single .so that exposes all 14 ixformer::infer functions
-# to Python via pybind11.  It links against the base image's existing
-# ixformer .so files at runtime (no static linking needed).
-#
-# Usage:
-#   cd /tmp/gdn_test/project_6 && bash ex_engine/build_unified_bridge.sh
-#
-# Output:
-#   ex_engine/build/ix_unified_bridge.cpython-310-x86_64-linux-gnu.so
-
+# build_unified_bridge.sh — Compile ix_unified_bridge.so on BI-V100
+# Uses manual compiler flags since torch.utils.cpp_extension is stripped from corex torch.
 set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
@@ -18,58 +8,49 @@ SRC_DIR="${SCRIPT_DIR}/csrc/ilu"
 BUILD_DIR="${SCRIPT_DIR}/build"
 mkdir -p "$BUILD_DIR"
 
-# Detect Python
 PYTHON=${PYTHON:-python3}
 PY_INC=$($PYTHON -c "import sysconfig; print(sysconfig.get_path('include'))")
 PY_SUFFIX=$($PYTHON -c "import sysconfig; print(sysconfig.get_config_var('EXT_SUFFIX'))")
 
-# Detect PyTorch
-TORCH_DIR=$($PYTHON -c "import torch; print(torch.utils.cmake_prefix_path)")
-TORCH_INC=$($PYTHON -c "import torch; print(torch.utils.cpp_extension.include_paths()[0])")
-TORCH_LIB=$($PYTHON -c "import torch; print(torch.utils.cpp_extension.library_paths()[0])")
+# Torch paths — manual discovery (no cpp_extension)
+TORCH_ROOT=$($PYTHON -c "import torch; import os; print(os.path.dirname(torch.__file__))")
+TORCH_INC="${TORCH_ROOT}/include"
+TORCH_INC2="${TORCH_ROOT}/include/torch/csrc/api/include"
+TORCH_LIB="${TORCH_ROOT}/lib"
 
-# Detect corex compiler (prefer) or system g++
-if [ -f /usr/local/corex/bin/clang++ ]; then
-    CXX=/usr/local/corex/bin/clang++
-    echo "[build] Using CoreX clang++: $CXX"
-elif [ -f /usr/local/corex/lib64/clang/16/bin/clang++ ]; then
-    CXX=/usr/local/corex/lib64/clang/16/bin/clang++
-    echo "[build] Using CoreX clang/16: $CXX"
-else
-    CXX=g++
-    echo "[build] Using system g++: $CXX"
-fi
+# Compiler: corex clang or system g++
+for _CXX in /usr/local/corex/bin/clang++ /usr/local/corex-3.2.3/bin/clang++ g++; do
+    [ -x "$_CXX" ] && CXX="$_CXX" && break
+done
+echo "[build] CXX=$CXX"
+echo "[build] TORCH_ROOT=$TORCH_ROOT"
+echo "[build] PY_INC=$PY_INC"
 
-echo "[build] Python include: $PY_INC"
-echo "[build] Torch include:  $TORCH_INC"
-echo "[build] Torch lib:      $TORCH_LIB"
-echo "[build] Output suffix:  $PY_SUFFIX"
-
-# Compile
 OUT="${BUILD_DIR}/ix_unified_bridge${PY_SUFFIX}"
 
 $CXX -shared -fPIC -O2 -std=c++17 \
     -I"$SRC_DIR" \
     -I"$PY_INC" \
     -I"$TORCH_INC" \
-    -I"$TORCH_INC/torch/csrc/api/include" \
+    -I"$TORCH_INC2" \
     -L"$TORCH_LIB" \
     -ltorch -ltorch_cpu -ltorch_cuda -lc10 -lc10_cuda \
-    -Wl,--no-as-needed \
+    -Wl,--no-as-needed,-rpath,"$TORCH_LIB" \
     -D_GLIBCXX_USE_CXX11_ABI=0 \
     -DTORCH_EXTENSION_NAME=ix_unified_bridge \
     "$SRC_DIR/ix_unified_bridge.cpp" \
-    -o "$OUT"
+    -o "$OUT" 2>&1
 
-echo "[build] SUCCESS: $OUT"
-ls -lh "$OUT"
-
-# Verify
-$PYTHON -c "
-import importlib.util, sys
+if [ -f "$OUT" ]; then
+    echo "[build] SUCCESS: $OUT ($(du -h "$OUT" | cut -f1))"
+    $PYTHON -c "
+import importlib.util
 spec = importlib.util.spec_from_file_location('ix_unified_bridge', '$OUT')
 mod = importlib.util.module_from_spec(spec)
 spec.loader.exec_module(mod)
 funcs = [x for x in dir(mod) if not x.startswith('_')]
-print(f'[verify] {len(funcs)} functions exported: {funcs}')
-" || echo "[verify] Import test requires ixformer runtime (expected on non-BI-V100)"
+print(f'[verify] {len(funcs)} functions: {funcs}')
+" 2>&1 || echo "[verify] import test needs ixformer runtime symbols"
+else
+    echo "[build] FAILED"
+fi