Fix is_managed reporting for pool-allocated managed memory

.gitignore

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

cuda_core/cuda/core/_memory/_buffer.pyx

@@ -391,7 +391,11 @@ cdef class Buffer:
     def is_managed(self) -> bool:
         """Return True if this buffer is CUDA managed (unified) memory, otherwise False."""
         _init_mem_attrs(self)
-        return self._mem_attrs.is_managed
+        if self._mem_attrs.is_managed:
+            return True
+        # Pool-allocated managed memory does not set CU_POINTER_ATTRIBUTE_IS_MANAGED,
+        # so fall back to the memory resource when it advertises managed allocations.
+        return self._memory_resource is not None and self._memory_resource.is_managed
 
     @property
     def is_mapped(self) -> bool:
@@ -535,6 +539,11 @@ 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")