fix(observation): validate document consistency during capture

apps/extension/src/browser-driver/__tests__/chromium-cdp.test.ts

@@ -29,6 +29,24 @@ function fakeApi() {
 }
 
 describe("ChromiumCdp", () => {
+  it("changes attachment identity only across real debugger attachments", async () => {
+    const { api, onEvent, onDetach } = fakeApi();
+    const cdp = new ChromiumCdp(api);
+    expect(cdp.getAttachmentId(4)).toBeUndefined();
+    await cdp.ensureAttached(4);
+    const first = cdp.getAttachmentId(4);
+    expect(first).toBeTruthy();
+    await cdp.ensureAttached(4);
+    onEvent.fire({ tabId: 4 }, "Target.attachedToTarget", { sessionId: "child" });
+    expect(cdp.getAttachmentId(4)).toBe(first);
+    onDetach.fire({ tabId: 4 }, "target_closed");
+    expect(cdp.getAttachmentId(4)).toBeUndefined();
+    await cdp.ensureAttached(4);
+    expect(cdp.getAttachmentId(4)).not.toBe(first);
+    await cdp.detach(4);
+    expect(cdp.getAttachmentId(4)).toBeUndefined();
+  });
+
   it("discovers multiple iframe targets and recursively routes nested OOPIF commands", async () => {
     const { api, onEvent } = fakeApi();
     (api.sendCommand as ReturnType<typeof vi.fn>).mockImplementation(

apps/extension/src/browser-driver/__tests__/frame-graph.test.ts

@@ -2,6 +2,24 @@ import { describe, expect, it } from "vitest";
 import { buildFrameGraph, type CdpFrameTreeNode, type CdpFrameTreeSource } from "../frame-graph";
 
 describe("buildFrameGraph", () => {
+  it("preserves the owning target's loader identity", () => {
+    const graph = buildFrameGraph([
+      {
+        target: { tabId: 4 },
+        tree: {
+          frame: { id: "root", loaderId: "root-loader" },
+          childFrames: [{ frame: { id: "child", loaderId: "stale-placeholder" } }],
+        },
+      },
+      {
+        target: { tabId: 4, sessionId: "child-session" },
+        tree: { frame: { id: "child", loaderId: "child-loader" } },
+      },
+    ]);
+    expect(graph?.frames.find((frame) => frame.frameId === "root")?.loaderId).toBe("root-loader");
+    expect(graph?.frames.find((frame) => frame.frameId === "child")?.loaderId).toBe("child-loader");
+  });
+
   it("keeps sibling frames distinct and routes nested OOPIFs to their child sessions", () => {
     const graph = buildFrameGraph([
       {