feat(sdk): 0.2.1——track补归属+business接线

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

sdk/test/business.test.ts

@@ -427,6 +427,19 @@ describe("business / startBusinessTracking", () => {
     expect(ids).toEqual(["cf7-156", "cf7-42", "cf7-0"]);
   });
 
+  it("form_id 回归（T4 审查遗留）：11 位 ID 不截断匹配 → cf7-0（服务端 cf7-N 上限 10 位）", () => {
+    setUrl("/fid11");
+    const t = mkTransport("biz-fid11");
+    startPageSession(t);
+    startBusinessTracking(t);
+    const form = mkForm({ action: "#wpcf7-f12345678901" });
+    trusted("focusin", form.querySelector("input")!);
+    t.flush();
+    const fss = fetchedEvents("biz-fid11").filter((e) => e.event_name === "form_start");
+    expect(fss).toHaveLength(1);
+    expect(fss[0].properties.form_id).toBe("cf7-0"); // (?!\d) 拒绝截断——按解析失败归 cf7-0
+  });
+
   // ---- product_view（spec §1.3：非锚定段匹配 + onSegmentChange 切段） ----
 
   it("product_view：init 时 /product/slug/ 判定 → inferred=true rule_version=v1 + 顶层归属", () => {