feat: [US-062] - Auto-migration of existing free-text values

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/editor/[projectId]/page.tsx

@@ -39,6 +39,10 @@ export default async function EditorPage({ params }: PageProps) {
     variables: rawData.variables || [],
   }
 
+  // Migration flag: if the raw data doesn't have characters/variables arrays,
+  // the project was created before these features existed and may need auto-migration
+  const needsMigration = !rawData.characters && !rawData.variables
+
   return (
     <div className="flex h-screen flex-col">
       <header className="flex items-center justify-between border-b border-zinc-200 bg-white px-4 py-3 dark:border-zinc-700 dark:bg-zinc-900">
@@ -70,6 +74,7 @@ export default async function EditorPage({ params }: PageProps) {
         <FlowchartEditor
           projectId={project.id}
           initialData={flowchartData}
+          needsMigration={needsMigration}
         />
       </div>
     </div>