Rename Activity tab to Agent View (#1773)

* rename Activity tab label to Agent View

Renames the user-visible tab label from 'Activity' to 'Agent View' in
the sidebar nav and the activity-page titlebar (plus matching tooltip
and aria-label). Internal view ID, store slice names, and component
filenames remain 'activity' to avoid behavioral risk — this is a pure
copy change.

* rename activity view labels to agents

---------

Co-authored-by: Jinjing <6427696+AmethystLiang@users.noreply.github.com>

src/renderer/src/components/activity/ActivityTitlebarControls.tsx

@@ -58,17 +58,17 @@ export function ActivityTitlebarControls(): React.JSX.Element {
               variant="ghost"
               size="icon-xs"
               onClick={closeActivityPage}
-              aria-label="Close activity"
+              aria-label="Close agents"
             >
               <ArrowLeft className="size-3.5" />
             </Button>
           </TooltipTrigger>
           <TooltipContent side="bottom" sideOffset={6}>
-            Close activity
+            Close agents
           </TooltipContent>
         </Tooltip>
         <Bell className="size-3.5 shrink-0 text-muted-foreground" />
-        <span className="truncate text-xs font-medium">Activity</span>
+        <span className="truncate text-xs font-medium">agents</span>
         <Badge variant="secondary" className="h-5 px-1.5 text-[11px] font-normal">
           {unreadCount} unread
         </Badge>

src/renderer/src/components/sidebar/SidebarNav.tsx

@@ -153,7 +153,7 @@ const SidebarNav = React.memo(function SidebarNav() {
           className={cn('size-4 shrink-0', !activityActive && 'text-sidebar-foreground/30')}
           strokeWidth={activityActive ? 2.25 : 1.75}
         />
-        <span className="flex-1">Activity</span>
+        <span className="flex-1">Agents</span>
         {activityUnreadCount > 0 ? (
           <span className="rounded-full bg-primary px-1.5 py-px text-[10px] font-semibold text-primary-foreground">
             {activityUnreadCount}