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/composer/index.tsx

@@ -103,6 +103,7 @@ import type {
 } from "@/attachments/types";
 import type { PickedFile } from "@/attachments/picked-file";
 import { composerWorkspaceAttachment } from "@/composer/attachments/workspace";
+import { useWorkspaceAttachmentsForScopes } from "@/attachments/workspace-attachments-store";
 import { droppedItemsToPickedFiles } from "@/composer/attachments/drop";
 import { getFileTypeLabel } from "@/attachments/file-types";
 import { Combobox, ComboboxItem, type ComboboxOption } from "@/components/ui/combobox";
@@ -121,6 +122,8 @@ type AttachmentListUpdater =
   | UserComposerAttachment[]
   | ((prev: UserComposerAttachment[]) => UserComposerAttachment[]);
 
+const EMPTY_ATTACHMENT_SCOPE_KEYS: readonly string[] = [];
+
 function noop() {}
 const noopCallback = () => {};
 
@@ -759,7 +762,7 @@ interface ComposerProps {
   value: string;
   onChangeText: (text: string) => void;
   attachments: UserComposerAttachment[];
-  workspaceAttachments?: readonly WorkspaceComposerAttachment[];
+  attachmentScopeKeys?: readonly string[];
   onOpenWorkspaceAttachment?: (attachment: WorkspaceComposerAttachment) => void;
   onChangeAttachments: (updater: AttachmentListUpdater) => void;
   cwd: string;
@@ -971,7 +974,7 @@ export function Composer({
   value,
   onChangeText,
   attachments,
-  workspaceAttachments = [],
+  attachmentScopeKeys = EMPTY_ATTACHMENT_SCOPE_KEYS,
   onOpenWorkspaceAttachment,
   onChangeAttachments,
   cwd,
@@ -1026,6 +1029,7 @@ export function Composer({
   const messagePlaceholder = resolveMessagePlaceholder(isDesktopLayout, t);
   const userInput = value;
   const setUserInput = onChangeText;
+  const workspaceAttachments = useWorkspaceAttachmentsForScopes(attachmentScopeKeys);
   const {
     selectedAttachments,
     buildOutgoingAttachments,