feat: xllm_ops NO-FALLBACK kernel loader + 6 missing .so build targets + hot-path patcher
Build infrastructure:
- build_xllm_kernels.sh: add 5 missing build targets (norm, rope, activation, cache, moe)
Previously only built xllm_fused_qknorm_rope.so, now builds all 6 .so files
Kernel loader (xllm_ops.py):
- NO-FALLBACK architecture matching xllm/core/kernels/ilu/ dispatch chain
- Loads: xllm_norm.so, xllm_rope.so, xllm_activation.so, xllm_cache.so,
xllm_moe.so, ix_full_bridge.so, xllm_fused_qknorm_rope.so
- check_all(strict=True) verifies ALL .so at startup
Hot-path patcher (patch_vllm_hot_path.py):
- Monkey-patches vllm._custom_ops to route through xllm .so
- Critical fix: topk_softmax patch prevents comp 168 cascade
- Patches: topk_softmax, rms_norm, silu_and_mul, rotary_embedding, reshape_and_cache
Source mapping: xllm/core/kernels/ilu/*.cpp -> our xllm_*.so files