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

app/Enums/DeclarationStatus.php

@@ -14,6 +14,8 @@ final class DeclarationStatus extends Enum
 
     const Termine = 'termine';
 
+    const MiseEnDemeure = 'mise_en_demeure';
+
     const Ferme = 'ferme';
 
     /**
@@ -28,6 +30,7 @@ final class DeclarationStatus extends Enum
             self::EnCours => 'En cours',
             self::EnAttenteClient => 'En attente client',
             self::Termine => 'Terminé',
+            self::MiseEnDemeure => 'Mise en demeure',
             self::Ferme => 'Fermé',
         ];
     }
@@ -42,8 +45,9 @@ final class DeclarationStatus extends Enum
         return [
             self::Created => [self::EnCours],
             self::EnCours => [self::EnAttenteClient, self::Termine],
-            self::EnAttenteClient => [self::EnCours],
+            self::EnAttenteClient => [self::EnCours, self::MiseEnDemeure],
             self::Termine => [self::Ferme],
+            self::MiseEnDemeure => [self::EnCours, self::Ferme],
             self::Ferme => [],
         ];
     }