Fix is_managed reporting for pool-allocated managed memory

Pool-allocated managed memory via cuMemAllocFromPoolAsync (from a pool
created with CU_MEM_ALLOCATION_TYPE_MANAGED) does not set
CU_POINTER_ATTRIBUTE_IS_MANAGED=1. _query_memory_attrs therefore
classified the allocation as pinned host memory, causing
classify_dl_device to return kDLCUDAHost instead of kDLCUDAManaged.
CCCL's make_tma_descriptor only accepts kDLCUDA or kDLCUDAManaged, so
as_tensor_map() failed with "Device type must be kDLCUDA or
kDLCUDAManaged" on managed buffers.

Buffer.is_device_accessible / is_host_accessible already delegate to
the memory resource when one is attached. Apply the same pattern to
is_managed, and expose is_managed on the MemoryResource base
(defaulting to False) with ManagedMemoryResource overriding it to
True.

Also ignore .claude/settings.local.json in .gitignore.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: cpcloud

.gitignore

@@ -196,3 +196,4 @@ cython_debug/
 
 # Cursor
 .cursorrules
+.claude/settings.local.json

cuda_core/cuda/core/_memory/_buffer.pyx

@@ -390,6 +390,8 @@ cdef class Buffer:
     @property
     def is_managed(self) -> bool:
         """Return True if this buffer is CUDA managed (unified) memory, otherwise False."""
+        if self._memory_resource is not None:
+            return self._memory_resource.is_managed
         _init_mem_attrs(self)
         return self._mem_attrs.is_managed
 
@@ -535,6 +537,11 @@ cdef class MemoryResource:
         """Whether buffers allocated by this resource are host-accessible."""
         raise TypeError("MemoryResource.is_host_accessible must be implemented by subclasses.")
 
+    @property
+    def is_managed(self) -> bool:
+        """Whether buffers allocated by this resource are CUDA managed (unified) memory."""
+        return False
+
     @property
     def device_id(self) -> int:
         """Device ID associated with this memory resource, or -1 if not applicable."""

cuda_core/cuda/core/_memory/_managed_memory_resource.pyx

@@ -121,6 +121,11 @@ cdef class ManagedMemoryResource(_MemPool):
         """Return True. This memory resource provides host-accessible buffers."""
         return True
 
+    @property
+    def is_managed(self) -> bool:
+        """Return True. This memory resource provides managed (unified) memory buffers."""
+        return True
+
 
 IF CUDA_CORE_BUILD_MAJOR >= 13:
     cdef tuple _VALID_LOCATION_TYPES = ("device", "host", "host_numa")