diff --git a/craft/src/state/PageContext.tsx b/craft/src/state/PageContext.tsx
index 9b73e15..f09d8b2 100644
--- a/craft/src/state/PageContext.tsx
+++ b/craft/src/state/PageContext.tsx
@@ -4,16 +4,13 @@ import { PageData } from '../types';
 import { SerializedTreeNode } from '../types/sitesmith';
 import { useSiteDesign, SiteDesign } from './SiteDesignContext';
 
-/** Layout components that accept children. Must match the .craft.rules.canMoveIn
- * config of each component. Leaf components (Heading, TextBlock, ButtonLink, …)
- * are NOT canvases and must serialize with isCanvas:false or their rendered
- * content gets swallowed by an empty drop-target wrapper. */
-const CANVAS_TYPES = new Set<string>([
-  'Container', 'Section', 'ColumnLayout', 'BackgroundSection',
-  'HeaderZone', 'FooterZone',
-  'HeroSimple', 'FeaturesGrid', 'CTASection',
-  'FormContainer', 'Navbar', 'Footer',
-]);
+/** Only `Container` instances are "real" canvases in serialized state — they
+ * directly render whatever is in node.data.nodes. Layout-shell components
+ * (Section, HeroSimple, FeaturesGrid, ColumnLayout, CTASection, etc) use
+ * Craft.js <Element canvas id="…"> linkedNodes internally; their own
+ * isCanvas must be FALSE or Craft.js's toNodeTree walker trips an Invariant
+ * because the shell claims to be a canvas but its render ignores `nodes`. */
+const CANVAS_TYPES = new Set<string>(['Container']);
 
 interface PageContextValue {
   pages: PageData[];
diff --git a/craft/src/utils/apply-ai-response.ts b/craft/src/utils/apply-ai-response.ts
index 99aadab..8c6e4f4 100644
--- a/craft/src/utils/apply-ai-response.ts
+++ b/craft/src/utils/apply-ai-response.ts
@@ -3,12 +3,12 @@ import type { NodeTree } from '@craftjs/core';
 import { usePages } from '../state/PageContext';
 import { SitesmithResponse, SerializedTreeNode } from '../types/sitesmith';
 
-/** Component types that act as drop targets (isCanvas = true) */
-const CANVAS_TYPES = new Set([
-  'Container', 'Section', 'ColumnLayout', 'BackgroundSection',
-  'HeroSimple', 'FeaturesGrid', 'CTASection',
-  'FormContainer', 'Navbar', 'Footer',
-]);
+/** Only Container is a "real" Craft.js canvas in serialized state. Layout
+ * shells (Section/HeroSimple/ColumnLayout/etc) use <Element canvas> linkedNodes
+ * internally — their own node must serialize with isCanvas:false or
+ * toNodeTree's walker hits an Invariant because the shell claims to be a
+ * canvas but its render ignores `data.nodes`. */
+const CANVAS_TYPES = new Set(['Container']);
 
 /**
  * Flatten a SerializedTreeNode tree into a Craft.js node map ready for