feat(desktop): unify unread pills into one shared UnreadPill component

desktop/src/features/messages/ui/MessageTimeline.tsx

@@ -1,5 +1,5 @@
 import * as React from "react";
-import { ArrowDown, ArrowUp, Hash } from "lucide-react";
+import { Hash } from "lucide-react";
 
 import {
   selectTimelineBodySurface,
@@ -11,9 +11,9 @@ import type { UserProfileLookup } from "@/features/profile/lib/identity";
 import type { ChannelType } from "@/shared/api/types";
 import { cn } from "@/shared/lib/cn";
 import { channelChrome } from "@/shared/layout/chromeLayout";
-import { Button } from "@/shared/ui/button";
 import { Spinner } from "@/shared/ui/spinner";
 import { TooltipProvider } from "@/shared/ui/tooltip";
+import { UnreadPill, unreadCountLabel } from "@/shared/ui/UnreadPill";
 import { UserAvatar } from "@/shared/ui/UserAvatar";
 import { TimelineSkeleton, useTimelineSkeletonRows } from "./TimelineSkeleton";
 import { TimelineMessageList } from "./TimelineMessageList";
@@ -313,17 +313,12 @@ const MessageTimelineBase = React.forwardRef<
               channelChrome.top,
             )}
           >
-            <Button
-              className="pointer-events-auto h-7 min-h-7 gap-1.5 rounded-full border-primary/40 bg-primary/10 px-2.5 text-2xs font-medium text-primary shadow-xs backdrop-blur-sm hover:bg-primary/20 [&_svg]:size-4"
-              data-testid="message-unread-pill"
+            <UnreadPill
+              direction="up"
+              label={unreadCountLabel(unreadCount)}
               onClick={handleJumpToOldestUnread}
-              size="sm"
-              type="button"
-              variant="outline"
-            >
-              <ArrowUp aria-hidden />
-              {`${unreadCount} new message${unreadCount === 1 ? "" : "s"}`}
-            </Button>
+              testId="message-unread-pill"
+            />
           </div>
         ) : null}
         <div
@@ -537,21 +532,18 @@ const MessageTimelineBase = React.forwardRef<
               hasComposerOverlay ? "bottom-36" : "bottom-4",
             )}
           >
-            <Button
-              className="pointer-events-auto h-7 min-h-7 gap-1.5 rounded-full border-border/50 bg-background/85 px-2.5 text-2xs font-medium text-muted-foreground shadow-xs backdrop-blur-sm hover:bg-muted/70 hover:text-foreground [&_svg]:size-4"
-              data-testid="message-scroll-to-latest"
+            <UnreadPill
+              direction="down"
+              label={
+                newMessageCount > 0
+                  ? unreadCountLabel(newMessageCount)
+                  : "Jump to latest"
+              }
               onClick={() => {
                 scrollToBottom("smooth");
               }}
-              size="sm"
-              type="button"
-              variant="outline"
-            >
-              <ArrowDown aria-hidden />
-              {newMessageCount > 0
-                ? `${newMessageCount} new message${newMessageCount === 1 ? "" : "s"}`
-                : "Jump to latest"}
-            </Button>
+              testId="message-scroll-to-latest"
+            />
           </div>
         ) : null}
       </div>

desktop/src/features/sidebar/ui/AppSidebar.tsx

@@ -1,8 +1,6 @@
 // biome-ignore format: keep compact to stay within file size limit
 import {
   Activity,
-  ArrowDown,
-  ArrowUp,
   Bot,
   FolderGit2,
   Home,
@@ -556,7 +554,6 @@ export function AppSidebar({
         {unreadAboveCount > 0 ? (
           <MoreUnreadButton
             count={unreadAboveCount}
-            icon={<ArrowUp />}
             onClick={scrollToNextAbove}
             position="top"
             testId="sidebar-more-unread-above"
@@ -768,7 +765,6 @@ export function AppSidebar({
           <MoreUnreadButton
             bottomClassName={unreadBelowBottomClass}
             count={unreadBelowCount}
-            icon={<ArrowDown />}
             onClick={scrollToNextBelow}
             position="bottom"
             testId="sidebar-more-unread-below"

desktop/src/features/sidebar/ui/MoreUnreadButton.tsx

@@ -1,21 +1,14 @@
-import type * as React from "react";
-
-import { Button } from "@/shared/ui/button";
-
-const MORE_UNREAD_BUTTON_CLASS =
-  "h-7 min-h-7 gap-1.5 rounded-full border-0 bg-primary px-2.5 text-2xs font-medium text-primary-foreground shadow-md hover:bg-primary/90 [&_svg]:size-4";
+import { UnreadPill, unreadCountLabel } from "@/shared/ui/UnreadPill";
 
 export function MoreUnreadButton({
   bottomClassName = "bottom-0",
   count,
-  icon,
   onClick,
   position,
   testId,
 }: {
   bottomClassName?: string;
   count: number;
-  icon: React.ReactNode;
   onClick: () => void;
   position: "top" | "bottom";
   testId: string;
@@ -24,17 +17,12 @@ export function MoreUnreadButton({
     <div
       className={`pointer-events-none absolute inset-x-0 z-10 flex justify-center py-1 ${position === "top" ? "top-0" : bottomClassName}`}
     >
-      <Button
-        className={`pointer-events-auto ${MORE_UNREAD_BUTTON_CLASS}`}
-        data-testid={testId}
+      <UnreadPill
+        direction={position === "top" ? "up" : "down"}
+        label={unreadCountLabel(count)}
         onClick={onClick}
-        size="sm"
-        type="button"
-        variant="ghost"
-      >
-        {icon}
-        {count} more unread
-      </Button>
+        testId={testId}
+      />
     </div>
   );
 }

desktop/src/shared/ui/UnreadPill.tsx

@@ -0,0 +1,37 @@
+import { ArrowDown, ArrowUp } from "lucide-react";
+
+import { Button } from "@/shared/ui/button";
+
+const UNREAD_PILL_CLASS =
+  "pointer-events-auto h-7 min-h-7 gap-1.5 rounded-full border-primary/40 bg-primary/10 px-2.5 text-2xs font-medium text-primary shadow-xs backdrop-blur-sm hover:bg-primary/20 [&_svg]:size-4";
+
+export function unreadCountLabel(count: number) {
+  return `${count} new message${count === 1 ? "" : "s"}`;
+}
+
+export function UnreadPill({
+  direction,
+  label,
+  onClick,
+  testId,
+}: {
+  direction: "up" | "down";
+  label: string;
+  onClick: () => void;
+  testId: string;
+}) {
+  const Arrow = direction === "up" ? ArrowUp : ArrowDown;
+  return (
+    <Button
+      className={UNREAD_PILL_CLASS}
+      data-testid={testId}
+      onClick={onClick}
+      size="sm"
+      type="button"
+      variant="outline"
+    >
+      <Arrow aria-hidden />
+      {label}
+    </Button>
+  );
+}