Fork assistant turns into new drafts (#1788)

* feat(chat): fork assistant turns into new drafts

Builds chat-history attachments on the daemon and routes them into draft composers so users can continue an assistant turn in an existing workspace tab or New Workspace.

* fix(chat): clean up fork draft handling

* fix(chat): address fork draft review feedback

* fix(server): build fork context from bounded timeline

* fix(app): restore assistant turn footer in streams

* fix(app): preserve fork draft setup

* fix(app): tighten assistant fork footers

* fix(app): lock active fork draft handoff

* fix(app): preserve attachment-only draft retries

* fix(app): unify composer attachment scopes

* fix(app): align chat history attachment labels

* fix(app): centralize attachment pill content

* fix(app): trim fork context for workspace naming

packages/app/src/stores/create-flow-store.test.ts

@@ -1,5 +1,5 @@
 import { beforeEach, describe, expect, it } from "vitest";
-import { useCreateFlowStore } from "./create-flow-store";
+import { isActiveCreateFlowForDraft, useCreateFlowStore } from "./create-flow-store";
 
 describe("create-flow-store", () => {
   beforeEach(() => {
@@ -88,4 +88,40 @@ describe("create-flow-store", () => {
 
     expect(useCreateFlowStore.getState().pendingByDraftId["draft-1"]).toBeUndefined();
   });
+
+  it("matches only active pending create flows for a draft and server", () => {
+    useCreateFlowStore.getState().setPending({
+      draftId: "draft-1",
+      serverId: "server-1",
+      agentId: null,
+      clientMessageId: "msg-1",
+      text: "hello",
+      timestamp: Date.now(),
+    });
+    const pending = useCreateFlowStore.getState().pendingByDraftId["draft-1"];
+
+    expect(
+      isActiveCreateFlowForDraft({
+        pending,
+        serverId: "server-1",
+        draftId: " draft-1 ",
+      }),
+    ).toBe(true);
+    expect(
+      isActiveCreateFlowForDraft({
+        pending,
+        serverId: "server-2",
+        draftId: "draft-1",
+      }),
+    ).toBe(false);
+
+    useCreateFlowStore.getState().markLifecycle({ draftId: "draft-1", lifecycle: "sent" });
+    expect(
+      isActiveCreateFlowForDraft({
+        pending: useCreateFlowStore.getState().pendingByDraftId["draft-1"],
+        serverId: "server-1",
+        draftId: "draft-1",
+      }),
+    ).toBe(false);
+  });
 });