fix(CQ-WEB-8): Add React.memo to performance-sensitive components

Wrap 7 list-item/card components with React.memo to prevent unnecessary
re-renders when parent components update but props remain unchanged:
- TaskItem (task lists)
- EventCard (calendar views)
- EntryCard (knowledge base)
- WorkspaceCard (workspace list)
- TeamCard (team list)
- DomainItem (domain list)
- ConnectionCard (federation connections)

All are pure components rendered inside .map() loops that depend solely
on their props for rendering output.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/components/tasks/TaskItem.tsx

@@ -1,4 +1,5 @@
 /* eslint-disable @typescript-eslint/no-unnecessary-condition */
+import React from "react";
 import type { Task } from "@mosaic/shared";
 import { TaskStatus, TaskPriority } from "@mosaic/shared";
 import { formatDate, isPastTarget, isApproachingTarget } from "@/lib/utils/date-format";
@@ -21,7 +22,7 @@ const priorityLabels: Record<TaskPriority, string> = {
   [TaskPriority.LOW]: "Low priority",
 };
 
-export function TaskItem({ task }: TaskItemProps): React.JSX.Element {
+export const TaskItem = React.memo(function TaskItem({ task }: TaskItemProps): React.JSX.Element {
   const statusIcon = statusIcons[task.status];
   const priorityLabel = priorityLabels[task.priority];
 
@@ -61,4 +62,4 @@ export function TaskItem({ task }: TaskItemProps): React.JSX.Element {
       </div>
     </div>
   );
-}
+});