fixes

Signed-off-by: Robert Kruszewski <github@robertk.io>

Author: robert3005

docs/developer-guide/internals/execution.md

@@ -133,10 +133,9 @@ pub trait ExecuteParentKernel<V: VTable> {
 }
 
 pub fn initialize(session: &VortexSession) {
-    let Some(kernels) = session.kernels() else {
-        return;
-    };
-    kernels.register_execute_parent_kernel(parent_id, Child, Kernel);
+    session
+        .kernels()
+        .register_execute_parent_kernel(parent_id, Child, Kernel);
 }
 ```
 

docs/developer-guide/internals/session.md

@@ -12,14 +12,15 @@ or other shared resources.
 
 The session is built on two primitives from the `vortex-session` crate:
 
-- **`VortexSession`** -- a cloneable, thread-safe map from Rust `TypeId` to a boxed value. Any
-  type that is `Send + Sync + Debug + 'static` can be stored as a session variable.
+- **`VortexSession`** -- a cloneable, thread-safe map from Rust `TypeId` to a shared
+  (`Arc`-wrapped) value. Any type that is `Clone + Send + Sync + Debug + 'static` can be stored
+  as a session variable.
 - **`Registry<T>`** -- a concurrent map from string IDs to values of type `T`, used by each
   component to look up registered plugins at runtime.
 
-Because `VortexSession` is backed by an `Arc<DashMap>`, cloning is cheap and all clones share
-the same state. This makes it safe to hand the session to multiple threads, tasks, or I/O
-operations without coordination.
+Because `VortexSession` is backed by an `ArcSwap`, cloning is cheap and all clones share the
+same state, with lock-free reads and copy-on-write writes. This makes it safe to hand the
+session to multiple threads, tasks, or I/O operations without coordination.
 
 ## Component Registries