[Feature] Add MiniCPM-SALA support (#30360)

Co-authored-by: Alex Nails <alex.nails@radixark.ai>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

python/sglang/srt/mem_cache/memory_pool.py

@@ -281,6 +281,7 @@ class ReqToTokenPool:
             )
         self.free_slots = list(range(1, self._alloc_size))
         self.req_generation = torch.zeros(self._alloc_size, dtype=torch.int64)
+        self._aux_cache: Any = None
 
     def write(self, indices, values):
         self.req_to_token[indices] = values
@@ -324,12 +325,41 @@ class ReqToTokenPool:
 
     def free(self, req: Req):
         assert req.req_pool_idx is not None, "request must have req_pool_idx"
+        if self._aux_cache is not None:
+            self._aux_cache.free(req.req_pool_idx)
         self.free_slots.append(req.req_pool_idx)
         req.req_pool_idx = None
 
     def clear(self):
         self.free_slots = list(range(1, self._alloc_size))
         self.req_generation.zero_()
+        if self._aux_cache is not None:
+            self._aux_cache.clear()
+
+    def attach_aux_cache(self, aux_cache: Any) -> None:
+        assert self._aux_cache is None
+        self._aux_cache = aux_cache
+
+    def reset_aux_cache_allocator(self) -> None:
+        if self._aux_cache is not None:
+            self._aux_cache.reset_allocator()
+
+    def schedulable_token_capacity(self, physical_capacity: int) -> int:
+        if self._aux_cache is None:
+            return physical_capacity
+        return self._aux_cache.dense_capacity
+
+    def alloc_aux_to_lengths(
+        self,
+        *,
+        req_pool_indices_cpu: torch.Tensor,
+        target_seq_lens_cpu: torch.Tensor,
+    ) -> None:
+        if self._aux_cache is not None:
+            self._aux_cache.alloc_to_lengths(
+                req_pool_indices_cpu=req_pool_indices_cpu,
+                target_seq_lens_cpu=target_seq_lens_cpu,
+            )
 
 
 class MambaPool: