feat(FN-5290): restore activity feed event map for typecheck in ActivityFee

Restores the activity feed event map in `ActivityFeed.tsx` that was missing after the merge, fixing a typecheck failure introduced by the prior commits.

Fusion-Task-Id: FN-5290

packages/dashboard/app/components/ActivityFeed.tsx

@@ -29,6 +29,7 @@ const TYPE_CONFIG: Record<ActivityFeedEntry["type"], {
   "task:created": { label: "Created", icon: Plus, color: "var(--todo)" },
   "task:moved": { label: "Moved", icon: ArrowRightLeft, color: "var(--in-progress)" },
   "task:updated": { label: "Updated", icon: Settings, color: "var(--text-muted)" },
+  "task:merge-worktree-reacquired": { label: "Merge Worktree Reacquired", icon: Settings, color: "var(--color-info)" },
   "task:deleted": { label: "Deleted", icon: XCircle, color: "var(--color-error)" },
   "task:merged": { label: "Merged", icon: GitMerge, color: "var(--color-success)" },
   "task:failed": { label: "Failed", icon: AlertTriangle, color: "var(--color-error)" },