Resolve a named read's offset when the graph compiles

The fold already holds the name and the read input's finished layout, so
the offset falls out there rather than at construction: `RecordLayout`
carries the resolved numbers and `set_layout` copies them into the read
slots. Constructors are untouched, and census-marker reads keep their
current installation.

A read meets the value type the name was written at, so a disagreement
between a read here and a write upstream is the same graph error as two
writes disagreeing; the one-name-one-type check now spans reads and
writes together. An absent attribute stays absent and the read serves
the forced default rather than reporting it.

`read_attribute` is the catalog's get half, typed and never `Option` at
the kernel boundary, with the name declared exactly as the write side
declares it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

node-graph/interpreted-executor/src/node_registry.rs

@@ -7,7 +7,7 @@ use graphene_std::raster::GPU;
 #[cfg(feature = "gpu")]
 use graphene_std::SourceId;
 use graphene_std::raster::{CPU, Raster};
-use graphene_std::registry::{ConstructionError, SourceHandle, NodeIOTypes, RegistryEntry};
+use graphene_std::registry::{ConstructionError, NodeIOTypes, RegistryEntry, SourceHandle};
 #[cfg(feature = "gpu")]
 use graphene_std::runtime::RuntimeHandle;
 
@@ -227,7 +227,9 @@ mod node_registry_macros {
 						let handle = inputs.next().unwrap();
 						let layout = handle.layout().clone();
 						let node = graphene_std::ops::IntoNode::<$to, _, $from>::new(handle.downcast_record::<$from>()?, &layout);
-						Ok(SourceHandle::new_record::<$to>(std::sync::Arc::new(node) as std::sync::Arc<core_types::registry::ErasedRecordNode>))
+						Ok(SourceHandle::new_record::<$to>(
+							std::sync::Arc::new(node) as std::sync::Arc<core_types::registry::ErasedRecordNode>
+						))
 					},
 				},
 			)