Release/0.6.2.post3: carry kt-kernel SwiGLU clamp companion missing from post2

kt-kernel/python/utils/amx.py

@@ -461,7 +461,17 @@ class NativeMoEWrapper(BaseMoEWrapper):
         max_deferred_experts_per_token: Optional[int] = None,
         method: str = "RAWINT4",
         numa_nodes: Optional[List[int]] = None,
+        swiglu_limit: float = 0.0,
     ):
+        # Defence in depth: reject swiglu_limit on non-MXFP4 methods even
+        # if the experts.py guard is bypassed (e.g., by a future caller
+        # that constructs NativeMoEWrapper directly). Origin: kt-sglang 耦合.
+        if swiglu_limit != 0.0 and method != "MXFP4":
+            raise ValueError(
+                f"NativeMoEWrapper received swiglu_limit={swiglu_limit} with "
+                f"method={method!r}; the V4-2604B clamp only applies to MXFP4. "
+                f"This indicates a missing guard in the caller."
+            )
         if method == "RAWINT4" and not (
             _HAS_RAWINT4_SUPPORT or _HAS_AVX2_RAWINT4_SUPPORT or _HAS_AVXVNNI256_RAW_INT4_SUPPORT
         ):
@@ -520,6 +530,7 @@ class NativeMoEWrapper(BaseMoEWrapper):
             max_deferred_experts_per_token=max_deferred_experts_per_token,
             method=method,
             numa_nodes=numa_nodes,
+            swiglu_limit=swiglu_limit,
         )
 
         if NativeMoEWrapper._native_loader_instance is None:
@@ -637,6 +648,20 @@ class NativeMoEWrapper(BaseMoEWrapper):
         moe_config.layer_idx = self.layer_idx
         moe_config.pool = self.cpu_infer.backend_
         moe_config.max_len = self.chunked_prefill_size
+        # V4-Flash 2604B SwiGLU clamp; 0.0 = disabled (default for non-MXFP4
+        # paths). Read by `act_fn` in operators/amx/la/amx.hpp via
+        # `apply_activation` in operators/amx/moe_base.hpp. Re-checked here
+        # (defence in depth) so a future caller that bypasses both the
+        # experts.py and the __init__ guards still cannot apply the clamp
+        # on RAWINT4 / FP8 / BF16 / FP8_PERCHANNEL / GPTQ_INT4 paths.
+        # Origin: kt-sglang 耦合.
+        if self.swiglu_limit != 0.0 and self.method != "MXFP4":
+            raise ValueError(
+                f"NativeMoEWrapper.load_weights: swiglu_limit="
+                f"{self.swiglu_limit} with method={self.method!r}; clamp is "
+                f"only valid for MXFP4."
+            )
+        moe_config.swiglu_limit = self.swiglu_limit
 
         # Use gate_projs instead of gate_proj for per-expert pointers
         moe_config.gate_projs = gate_ptrs