Faza 2: multi-tenancy + Filament dual panels + seed PSauto

Schema centrală:
- companies (slug unique, status, plan_id, settings JSON, trial/active dates)
- super_admins (operator platform)
- plans (free/basic/pro)

Schema tenant (toate cu company_id NOT NULL):
- users (UNIQUE company_id+email)
- clients
- vehicles

Tenancy core:
- App\Tenancy\TenantManager singleton
- App\Models\Concerns\BelongsToTenant trait + TenantScope
- ResolveTenant middleware (slug → Company, 404 pentru rezervate/missing)
- CheckTenantStatus middleware (suspended/expired/archived)
- Fail-safe: TenantScope returns 0 rows când tenant nu e rezolvat

Auth guards:
- 'central' guard cu super_admins provider (panou platform)
- 'web' guard cu users provider (per-tenant)

Filament panels:
- CentralPanelProvider la service.mir.md/admin
- TenantPanelProvider la <slug>.service.mir.md/app
- CompanyResource (central): CRUD companii cu status badge + filtre
- ClientResource (tenant): CRUD clienți cu status, sursă, sold
- VehicleResource (tenant): CRUD mașini cu marcă/model/VIN

Seed:
- 3 plans (free/basic/pro)
- super-admin: vasyka.moraru@gmail.com / admin123
- demo company 'psauto' cu admin user admin@psauto.md / admin123
- 3 clienți + 3 mașini preluate din AutoCRM.html

Bootstrap:
- TrustProxies (Cloudflare→Traefik HTTPS detection)
- forceScheme/forceRootUrl când APP_URL e HTTPS
- Helper global tenant() în app/helpers.php (autoload via composer)
- RUN_SEED env var în entrypoint pentru db:seed condiționat

composer.json

@@ -29,7 +29,10 @@
             "App\\": "app/",
             "Database\\Factories\\": "database/factories/",
             "Database\\Seeders\\": "database/seeders/"
-        }
+        },
+        "files": [
+            "app/helpers.php"
+        ]
     },
     "autoload-dev": {
         "psr-4": {