feat: implement Story 2.4 — Dashboard Activity Feed with review fixes

Add role-scoped activity feed to the dashboard showing the 20 most recent
workspace events. Owners/Managers see all activity (declarations, clients,
team changes); Workers see only their assigned declarations. Includes
French descriptions, relative timestamps, responsive layout (desktop
sidebar, tablet inline, mobile collapsible), and 7 passing Pest tests.

Review fixes applied: batch-load declarations/clients/users to eliminate
N+1 queries, consistent soft-delete handling in URL resolution, French
grammar singular/plural fix, missing icon map entry, and corrected tablet
breakpoint per spec.

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

resources/js/types/dashboard.ts

@@ -36,11 +36,23 @@ export type DashboardAlert = {
     showUrl: string;
 };
 
+export type ActivityEvent = {
+    id: number;
+    actorName: string;
+    actorInitials: string;
+    description: string;
+    targetUrl: string | null;
+    targetLabel: string | null;
+    timestamp: string;
+    eventType: string;
+};
+
 export type DashboardProps = {
     stats: DashboardStats | null;
     statCards: StatCardLink[];
     declarations: DashboardDeclaration[];
     alerts: DashboardAlert[];
+    activities: ActivityEvent[];
     workspaceName: string | null;
     roleLabel: string | null;
     isWorker: boolean;