Auto-attach pasted GitHub PR/issue URLs in the composer (#1006)

* Auto-attach pasted GitHub PR/issue URLs in the composer

Paste a GitHub PR or issue link into any composer and it shows up
as an attachment pill within a debounce tick when the URL matches
the workspace's remote. On the new-workspace screen, an attached PR
also surfaces an inline "Check out PR #N?" hint next to the picker;
one click promotes it to the checkout target through the same
syncPickerPrAttachment flow the dropdown uses.

Unifies the new-workspace picker and composer attachment picker on
one shared GitHub search hook and cache key, so both consumers (and
the auto-attach lookup) share the React Query cache.

* Fix oxfmt formatting in new-workspace-screen import

packages/app/src/components/composer.tsx

@@ -21,7 +21,6 @@ import {
   Paperclip,
 } from "lucide-react-native";
 import Animated from "react-native-reanimated";
-import { useQuery } from "@tanstack/react-query";
 import { FOOTER_HEIGHT, MAX_CONTENT_WIDTH } from "@/constants/layout";
 import {
   AgentStatusBar,
@@ -53,7 +52,7 @@ import {
   queueComposerMessage,
   removeComposerAttachmentAtIndex,
   sendQueuedComposerMessageNow,
-  toggleGithubAttachment,
+  toggleGithubAttachmentFromPicker,
   type AgentStreamWriter,
   type QueueWriter,
   type QueuedComposerMessage,
@@ -97,6 +96,9 @@ import { AttachmentPill } from "@/components/attachment-pill";
 import { AttachmentLightbox } from "@/components/attachment-lightbox";
 import { openExternalUrl } from "@/utils/open-external-url";
 import { useIsDictationReady } from "@/hooks/use-is-dictation-ready";
+import { useGithubSearchQuery } from "@/git/use-github-search-query";
+import { useCheckoutStatusQuery } from "@/git/use-status-query";
+import { useComposerGithubAutoAttach } from "./use-composer-github-auto-attach";
 
 type QueuedMessage = QueuedComposerMessage;
 
@@ -137,6 +139,20 @@ function resolveMessagePlaceholder(isDesktopWebBreakpoint: boolean): string {
   return isDesktopWebBreakpoint ? DESKTOP_MESSAGE_PLACEHOLDER : MOBILE_MESSAGE_PLACEHOLDER;
 }
 
+function resolveGithubSearchEnabled(
+  isGithubPickerOpen: boolean,
+  isConnected: boolean,
+  cwd: string,
+): boolean {
+  return isGithubPickerOpen && isConnected && cwd.trim().length > 0;
+}
+
+function resolveCheckoutRemoteUrl(
+  checkoutStatus: ReturnType<typeof useCheckoutStatusQuery>["status"],
+): string | null {
+  return checkoutStatus?.remoteUrl ?? null;
+}
+
 function buildCancelButtonStyle(isConnected: boolean, isCancellingAgent: boolean): object[] {
   const disabled = !isConnected || isCancellingAgent ? styles.buttonDisabled : undefined;
   return [styles.cancelButton, disabled].filter((value): value is object => Boolean(value));
@@ -164,31 +180,6 @@ function buildAgentStateSelector(serverId: string, agentId: string) {
   };
 }
 
-interface BuildGithubSearchQueryOptionsArgs {
-  serverId: string;
-  cwd: string;
-  githubSearchQueryTrimmed: string;
-  isGithubPickerOpen: boolean;
-  isConnected: boolean;
-  client: ReturnType<typeof useHostRuntimeClient>;
-}
-
-function buildGithubSearchQueryOptions(args: BuildGithubSearchQueryOptionsArgs) {
-  const { serverId, cwd, githubSearchQueryTrimmed, isGithubPickerOpen, isConnected, client } = args;
-  const hasClient = Boolean(client);
-  const cwdIsSet = cwd.trim().length > 0;
-  const enabled = isGithubPickerOpen && isConnected && hasClient && cwdIsSet;
-  return {
-    queryKey: ["composer-github-search", serverId, cwd, githubSearchQueryTrimmed],
-    queryFn: async () => {
-      if (!client) throw new Error("Host is not connected");
-      return client.searchGitHub({ cwd, query: githubSearchQueryTrimmed, limit: 20 });
-    },
-    enabled,
-    staleTime: 30_000,
-  };
-}
-
 function renderContextWindowMeterSlot(
   contextWindowMaxTokens: number | null,
   contextWindowUsedTokens: number | null,
@@ -890,6 +881,17 @@ export function Composer({
     onOpenWorkspaceAttachment,
   });
   const setSelectedAttachments = onChangeAttachments;
+  const checkoutStatusQuery = useCheckoutStatusQuery({ serverId, cwd });
+  const githubAutoAttach = useComposerGithubAutoAttach({
+    text: userInput,
+    remoteUrl: resolveCheckoutRemoteUrl(checkoutStatusQuery.status),
+    attachments,
+    client,
+    isConnected,
+    serverId,
+    cwd,
+    setAttachments: setSelectedAttachments,
+  });
   const [cursorIndex, setCursorIndex] = useState(0);
   const [isProcessing, setIsProcessing] = useState(false);
   const [isCancellingAgent, setIsCancellingAgent] = useState(false);
@@ -1135,6 +1137,7 @@ export function Composer({
 
   const handleRemoveAttachment = useCallback(
     (index: number) => {
+      githubAutoAttach.markGithubAttachmentRemoved(selectedAttachments[index]);
       const didRemoveWorkspaceAttachment = removeAttachment({
         selectedAttachments,
         index,
@@ -1146,7 +1149,7 @@ export function Composer({
         removeComposerAttachmentAtIndex({ attachments: prev, index, deleteAttachments }),
       );
     },
-    [removeAttachment, selectedAttachments, setSelectedAttachments],
+    [githubAutoAttach, removeAttachment, selectedAttachments, setSelectedAttachments],
   );
 
   const handleOpenAttachment = useCallback(
@@ -1376,16 +1379,13 @@ export function Composer({
   );
 
   const githubSearchQueryTrimmed = githubSearchQuery.trim();
-  const githubSearchResultsQuery = useQuery(
-    buildGithubSearchQueryOptions({
-      serverId,
-      cwd,
-      githubSearchQueryTrimmed,
-      isGithubPickerOpen,
-      isConnected,
-      client,
-    }),
-  );
+  const githubSearchResultsQuery = useGithubSearchQuery({
+    client,
+    serverId,
+    cwd,
+    query: githubSearchQueryTrimmed,
+    enabled: resolveGithubSearchEnabled(isGithubPickerOpen, isConnected, cwd),
+  });
 
   const githubSearchItemsRaw = githubSearchResultsQuery.data?.items;
   const githubSearchItems = useMemo(() => githubSearchItemsRaw ?? [], [githubSearchItemsRaw]);
@@ -1423,11 +1423,22 @@ export function Composer({
 
   const handleToggleGithubItem = useCallback(
     (item: GitHubSearchItem) => {
-      setSelectedAttachments((current) => toggleGithubAttachment(current, item));
+      const nextAttachments = toggleGithubAttachmentFromPicker({
+        current: attachments,
+        item,
+        markGithubAttachmentRemoved: githubAutoAttach.markGithubAttachmentRemoved,
+      });
+      setSelectedAttachments(nextAttachments);
       setIsGithubPickerOpen(false);
       setGithubSearchQuery("");
     },
-    [setSelectedAttachments, setGithubSearchQuery, setIsGithubPickerOpen],
+    [
+      attachments,
+      githubAutoAttach,
+      setSelectedAttachments,
+      setGithubSearchQuery,
+      setIsGithubPickerOpen,
+    ],
   );
 
   const leftContent = useMemo(