Style the work drawer as a secondary-surface container

The work module's contents (label, branch chip, PR card) sit in a
rounded secondary-background container, the divider against the
conversation is gone, and the drawer eases open/closed on its width
(300ms ease-out) instead of popping — the panel stays mounted so the
close animates too.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

desktop/src/features/chats/ui/ChatDetail.tsx

@@ -624,8 +624,8 @@ export function ChatDetail({
             />
           </div>
         </div>
-        {workPanelHref && showWorkPanel ? (
-          <ChatWorkPanel prHref={workPanelHref} />
+        {workPanelHref ? (
+          <ChatWorkPanel open={showWorkPanel} prHref={workPanelHref} />
         ) : null}
       </div>
     </>

desktop/src/features/chats/ui/ChatWorkPanel.tsx

@@ -5,14 +5,22 @@ import {
   useGithubPullRequestQuery,
 } from "@/shared/lib/githubPullRequest";
 import { parseSupportedLinkPreview } from "@/shared/lib/linkPreview";
+import { cn } from "@/shared/lib/cn";
 import { GithubPullRequestCard } from "@/shared/ui/link-preview-attachment";
 
 /**
  * Right-hand work module for a chat whose agent produced a pull request:
- * the PR's source branch and the live PR card (status, diff stats, link).
- * The conversation column and composer shrink to make room.
+ * the PR's source branch and the live PR card (status, diff stats, link),
+ * grouped in a secondary-surface container. The drawer eases open/closed on
+ * its width so the conversation column and composer slide to make room.
  */
-export function ChatWorkPanel({ prHref }: { prHref: string }) {
+export function ChatWorkPanel({
+  open = true,
+  prHref,
+}: {
+  open?: boolean;
+  prHref: string;
+}) {
   const preview = parseSupportedLinkPreview(prHref);
   const ref = parseGithubPullRequestRef(prHref);
   const query = useGithubPullRequestQuery(ref);
@@ -24,19 +32,28 @@ export function ChatWorkPanel({ prHref }: { prHref: string }) {
 
   return (
     <aside
-      className="flex w-80 shrink-0 flex-col gap-3 overflow-y-auto border-l border-border/40 px-4 py-4"
+      aria-hidden={!open}
+      className={cn(
+        "flex shrink-0 flex-col overflow-hidden transition-[width,opacity] duration-300 ease-out",
+        open ? "w-80 opacity-100" : "pointer-events-none w-0 opacity-0",
+      )}
       data-testid="chat-work-panel"
     >
-      <div className="text-2xs font-semibold uppercase tracking-wide text-muted-foreground">
-        Work
-      </div>
-      {branch ? (
-        <div className="flex items-center gap-1.5 rounded-lg border border-border/60 bg-muted/20 px-3 py-2 text-xs">
-          <GitBranch className="h-3.5 w-3.5 shrink-0 text-muted-foreground" />
-          <span className="min-w-0 truncate font-mono">{branch}</span>
+      {/* Fixed-width inner wrapper so content never reflows mid-slide. */}
+      <div className="w-80 overflow-y-auto py-4 pl-1 pr-4">
+        <div className="flex flex-col gap-3 rounded-2xl bg-secondary p-3">
+          <div className="text-2xs font-semibold uppercase tracking-wide text-muted-foreground">
+            Work
+          </div>
+          {branch ? (
+            <div className="flex items-center gap-1.5 rounded-lg bg-background/60 px-3 py-2 text-xs">
+              <GitBranch className="h-3.5 w-3.5 shrink-0 text-muted-foreground" />
+              <span className="min-w-0 truncate font-mono">{branch}</span>
+            </div>
+          ) : null}
+          <GithubPullRequestCard className="w-full" preview={preview} />
         </div>
-      ) : null}
-      <GithubPullRequestCard className="w-full" preview={preview} />
+      </div>
     </aside>
   );
 }

desktop/tests/e2e/chats-first-message.spec.ts

@@ -1,5 +1,6 @@
 import { expect, test } from "@playwright/test";
 
+import { waitForAnimations } from "../helpers/animations";
 import { installMockBridge } from "../helpers/bridge";
 
 test("first message in a new chat is sent and rendered", async ({ page }) => {
@@ -159,5 +160,6 @@ test("first message in a new chat is sent and rendered", async ({ page }) => {
   await expect(workPanel).not.toBeVisible();
   await page.getByTestId("toggle-work-panel").click();
   await expect(workPanel).toBeVisible();
+  await waitForAnimations(page);
   await page.screenshot({ path: "test-results/agent-pr-card.png" });
 });