feat: 新增 GraphTracer 并重构 ArrayTracer 的初始化方式

- 新增 GraphTracer 及其类型定义，支持图的创建和操作命令
- 重构 ArrayTracer 的 create 函数，使用 walker/commit 模式替代直接的 array 参数，提高灵活性
- 更新类型导出和命令联合类型以包含 GraphTracer
- 调整示例代码以使用新的初始化方式

tracers.ts/src/tracers/array-tracer.ts

@@ -1,15 +1,32 @@
 import { getTracerContext } from '../context';
 import type { JsonValue } from '../types';
 
-interface ArrayTracerCreateOptions<T extends JsonValue[]> {
+interface BaseArrayTracerCreateOptions {
   description?: string;
-  array?: T;
 }
 
+interface ArrayTracerCreateOptionsFromArray<
+  T extends JsonValue[],
+> extends BaseArrayTracerCreateOptions {
+  array: T;
+  walker?: never;
+}
+
+interface ArrayTracerCreateOptionsFromWalker<
+  T extends JsonValue[],
+> extends BaseArrayTracerCreateOptions {
+  array?: never;
+  walker: (commit: (item: T[number]) => void) => void;
+}
+
+type ArrayTracerCreateOptions<T extends JsonValue[]> =
+  | ArrayTracerCreateOptionsFromArray<T>
+  | ArrayTracerCreateOptionsFromWalker<T>;
+
 export const createArrayTracer = <T extends JsonValue[]>(
   options: ArrayTracerCreateOptions<T>,
 ) => {
-  const { description, array } = options;
+  const { description, array, walker } = options;
   const tracer = crypto.randomUUID();
 
   // 优化：仅维护数组长度作为影子状态，这在 C++/Java 等强类型语言中也极易实现（仅需一个 int 变量）

tracers.ts/src/tracers/graph-tracer.ts

@@ -0,0 +1,33 @@
+import { getTracerContext } from '../context';
+import type { GraphTracerGraph } from '../types';
+
+interface GraphTracerCreateOptions {
+  description?: string;
+  graph?: GraphTracerGraph;
+}
+
+// 不要了，改为 walker/commit 方案
+// TODO: 后续我们会添加创建图的辅助函数
+// export const createGraphTracerHelper = () => {};
+
+export const createGraphTracer = (options: GraphTracerCreateOptions) => {
+  const { description, graph } = options;
+  const tracer = crypto.randomUUID();
+
+  const { command } = getTracerContext();
+
+  command({
+    type: 'GraphTracer',
+    tracer: tracer,
+    action: 'create',
+    params: {
+      description: description ?? 'GraphTracer',
+      graph: graph ?? {
+        directed: false,
+        weighted: false,
+        nodes: [],
+        edges: [],
+      },
+    },
+  });
+};

tracers.ts/src/tracers/index.ts

@@ -1,3 +1,4 @@
 export * from './array-tracer';
 export * from './control-tracer';
+export * from './graph-tracer';
 export * from './log-tracer';