feat: [US-002] - Define TypeScript types for flowchart data

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

package.json

@@ -6,7 +6,8 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
-    "lint": "eslint"
+    "lint": "eslint",
+    "typecheck": "tsc --noEmit"
   },
   "dependencies": {
     "@supabase/ssr": "^0.8.0",

src/types/flowchart.ts

@@ -0,0 +1,73 @@
+// Position type for node coordinates
+export type Position = {
+  x: number;
+  y: number;
+};
+
+// DialogueNode type: represents character speech/dialogue
+export type DialogueNode = {
+  id: string;
+  type: 'dialogue';
+  position: Position;
+  data: {
+    speaker?: string;
+    text: string;
+  };
+};
+
+// Choice option type for ChoiceNode
+export type ChoiceOption = {
+  id: string;
+  label: string;
+};
+
+// ChoiceNode type: represents branching decisions
+export type ChoiceNode = {
+  id: string;
+  type: 'choice';
+  position: Position;
+  data: {
+    prompt: string;
+    options: ChoiceOption[];
+  };
+};
+
+// VariableNode type: represents variable operations
+export type VariableNode = {
+  id: string;
+  type: 'variable';
+  position: Position;
+  data: {
+    variableName: string;
+    operation: 'set' | 'add' | 'subtract';
+    value: number;
+  };
+};
+
+// Union type for all node types
+export type FlowchartNode = DialogueNode | ChoiceNode | VariableNode;
+
+// Condition type for conditional edges
+export type Condition = {
+  variableName: string;
+  operator: '>' | '<' | '==' | '>=' | '<=' | '!=';
+  value: number;
+};
+
+// FlowchartEdge type: represents connections between nodes
+export type FlowchartEdge = {
+  id: string;
+  source: string;
+  sourceHandle?: string;
+  target: string;
+  targetHandle?: string;
+  data?: {
+    condition?: Condition;
+  };
+};
+
+// FlowchartData type: represents the complete flowchart structure
+export type FlowchartData = {
+  nodes: FlowchartNode[];
+  edges: FlowchartEdge[];
+};