fix(web): pull request surface offers the checkout's PR

apps/web/src/components/ChatView.tsx

@@ -4406,14 +4406,28 @@ function ChatViewContent(props: ChatViewProps) {
     linkedPullRequest: linkedThreadPullRequest,
     linkedPullRequestStatus,
   });
-  // The right panel offers the thread's own change request, so it can only offer it once the
-  // branch has one; until then the picker says so rather than opening an empty panel.
+  // The right panel offers the thread's own change request, else the checkout's open one: the
+  // same one the git menu's "View PR" opens in this panel. A shared checkout keeps the recorded
+  // thread branch strict (#4460), so an agent that branches and opens a PR mid-thread leaves the
+  // thread without one while the checkout has it. A linked PR is the thread's own even while
+  // its detail is still loading, so the checkout never stands in for it. Without either the
+  // picker says so rather than opening an empty panel.
+  const checkoutPr =
+    linkedThreadPullRequest === null && gitStatusQuery.data?.pr?.state === "open"
+      ? gitStatusQuery.data.pr
+      : null;
   const addPullRequestSurface = useCallback(() => {
-    if (activeThreadPr === null) return;
-    openThreadPullRequest(activeThreadPr.number);
-  }, [activeThreadPr, openThreadPullRequest]);
+    if (activeThreadPr !== null) {
+      openThreadPullRequest(activeThreadPr.number);
+    } else if (checkoutPr !== null) {
+      openProjectPullRequest(checkoutPr.number);
+    }
+  }, [activeThreadPr, checkoutPr, openProjectPullRequest, openThreadPullRequest]);
   const pullRequestSurfaceAvailable =
-    supportsPullRequests && activeThreadPr !== null && threadRepository !== null;
+    supportsPullRequests &&
+    (activeThreadPr !== null
+      ? threadRepository !== null
+      : checkoutPr !== null && activeProjectRepository !== null);
   // Primitive slice of the displayed PR for the settle-rule memos below:
   // resolveDisplayedThreadPr returns a fresh object every render, so memoize
   // on the fields the rules read instead of the object identity.

apps/web/src/components/RightPanelTabs.tsx

@@ -99,7 +99,7 @@ const SURFACE_DISABLED_REASONS = {
   terminal: "Terminal surfaces are only available from a project thread.",
   files: "Files are only available when a project is open.",
   diff: "Diff is only available for server threads in Git repositories.",
-  pullRequest: "This thread's branch has no pull request yet.",
+  pullRequest: "This branch has no pull request yet.",
   agents: "Agents are only available from a thread.",
 } as const;