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>

tests/Feature/Dashboard/WorkerDashboardTest.php

@@ -267,6 +267,23 @@ test('owner and manager dashboard returns isWorker false', function () {
     );
 });
 
+test('worker without workspace session gets isWorker false in fallback', function () {
+    $worker = User::factory()->create();
+    $workspace = Workspace::factory()->create();
+    $workspace->users()->attach($worker->id, ['role' => 'worker']);
+
+    // No session(['current_workspace_id' => ...]) — simulate no active workspace
+    $this->actingAs($worker);
+    $response = $this->get(route('dashboard'));
+
+    $response->assertOk();
+    $response->assertInertia(fn ($page) => $page
+        ->component('Dashboard')
+        ->where('isWorker', false)
+        ->where('workspaceName', null)
+    );
+});
+
 test('cached data is scoped per user with worker cache key including user id', function () {
     [$worker, $workspace, $client] = setupWorkerWorkspace();