feat: implement Story 2.1 — Owner/Manager Command Center Dashboard

- Rewrite DashboardController with cached role-scoped KPI aggregation
  (Cache::remember, 5-min TTL, Declaration::forUser scope)
- Create StatCard.vue component with CVA status variants and a11y
- Rewrite Dashboard.vue with 4-column KPI grid + urgent declarations table
- Add mise_en_demeure status to DeclarationStatus enum with transitions
- Exclude termine, mise_en_demeure, ferme from dashboard queries
- Set deadline proximity red threshold to ≤5 days
- Add abort(404) for non-member workspace access per architecture
- Fix null-safe client access for soft-deleted clients
- Fix hardcoded routes with Wayfinder type-safe imports
- Fix DashboardProps.stats type to allow null
- Add aria-pressed to StatCard for accessibility
- Install shadcn-vue table component (11 files)
- Add 11 Pest feature tests + 3 mise_en_demeure transition tests
- Fix DeclarationFactory eager workspace creation causing slug collisions
- 196 tests pass, 836 assertions, zero regressions

database/factories/DeclarationFactory.php

@@ -21,9 +21,6 @@ class DeclarationFactory extends Factory
      */
     public function definition(): array
     {
-        $workspace = Workspace::factory()->create();
-        $client = Client::factory()->create(['workspace_id' => $workspace->id]);
-
         $year = fake()->numberBetween(2024, 2026);
         $excludeOldVat = array_filter(DeclarationType::getValues(), fn ($v) => $v !== 'vat');
         $type = fake()->randomElement(array_values($excludeOldVat));
@@ -32,8 +29,10 @@ class DeclarationFactory extends Factory
         $isVatQuarterly = $type === 'vat_quarterly';
 
         return [
-            'workspace_id' => $workspace->id,
-            'client_id' => $client->id,
+            'workspace_id' => Workspace::factory(),
+            'client_id' => function (array $attributes) {
+                return Client::factory()->create(['workspace_id' => $attributes['workspace_id']])->id;
+            },
             'created_by' => null,
             'title' => 'Déclaration '.$this->typeLabel($type).' - '.$year,
             'type' => $type,

database/factories/WorkspaceFactory.php

@@ -17,7 +17,7 @@ class WorkspaceFactory extends Factory
      */
     public function definition(): array
     {
-        $name = fake()->company();
+        $name = fake()->unique()->company();
         $slug = Str::slug($name);
 
         return [