feat: [US-059] - Variable node variable dropdown

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

src/components/editor/EditorContext.tsx

@@ -0,0 +1,24 @@
+'use client'
+
+import { createContext, useContext } from 'react'
+import type { Character, Variable } from '@/types/flowchart'
+
+type EditorContextValue = {
+  characters: Character[]
+  onAddCharacter: (name: string, color: string) => string // returns new character id
+  variables: Variable[]
+  onAddVariable: (name: string, type: 'numeric' | 'string' | 'boolean', initialValue: number | string | boolean) => string // returns new variable id
+}
+
+const EditorContext = createContext<EditorContextValue>({
+  characters: [],
+  onAddCharacter: () => '',
+  variables: [],
+  onAddVariable: () => '',
+})
+
+export const EditorProvider = EditorContext.Provider
+
+export function useEditorContext() {
+  return useContext(EditorContext)
+}