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/e2e/helpers/agent-bottom-anchor.ts

@@ -55,6 +55,25 @@ export async function expectNearBottom(page: Page): Promise<void> {
     .toBeLessThanOrEqual(NEAR_BOTTOM_THRESHOLD_PX);
 }
 
+export async function scrollAgentChatToBottom(page: Page): Promise<void> {
+  const chatScroll = getVisibleChatScroll(page);
+  await chatScroll.evaluate((root: Element) => {
+    const scrollElement = root as HTMLElement;
+    scrollElement.scrollTop = scrollElement.scrollHeight;
+  });
+  await expect
+    .poll(async () =>
+      chatScroll.evaluate((root: Element) => {
+        const scrollElement = root as HTMLElement;
+        return Math.max(
+          0,
+          scrollElement.scrollHeight - (scrollElement.scrollTop + scrollElement.clientHeight),
+        );
+      }),
+    )
+    .toBeLessThanOrEqual(NEAR_BOTTOM_THRESHOLD_PX);
+}
+
 export async function waitForContentGrowth(
   page: Page,
   previousContentHeight: number,

packages/app/e2e/helpers/mock-agent.ts

@@ -1,7 +1,7 @@
 import type { Page } from "@playwright/test";
-import { buildHostWorkspaceRoute } from "../../src/utils/host-routes";
 import { seedWorkspace, type SeedDaemonClient } from "./seed-client";
 import { getServerId } from "./server-id";
+import { buildHostAgentDetailRoute } from "../../src/utils/host-routes";
 
 export interface MockAgentWorkspace {
   agentId: string;
@@ -54,9 +54,7 @@ export async function seedMockAgentWorkspace(
 }
 
 export function buildAgentRoute(workspaceId: string, agentId: string): string {
-  return `${buildHostWorkspaceRoute(getServerId(), workspaceId)}?open=${encodeURIComponent(
-    `agent:${agentId}`,
-  )}`;
+  return buildHostAgentDetailRoute(getServerId(), agentId, workspaceId);
 }
 
 /** Boots the app directly at the agent's workspace route and waits for the open intent to settle. */