Central panel SaaS upgrade — Plans/Subscriptions/SuperAdmins/Detail page

Models & migrations:
- subscriptions table (company, plan, period, amount, status, dates, invoice)
- super_admins: role enum (owner/admin/support/sales/finance) + phone + notes
- Subscription model with STATUSES/PERIODS/PAYMENT_METHODS + invoice number
  generator + extends company.active_until on mark_paid
- Company model: subscriptions() + latestSubscription() relations
- SuperAdmin model: role helpers (isOwner, canManageBilling, canManageTenants)

Filament Central panel:
- PlanResource (CRUD, features checklist, limits per plan, abonati count badge)
- SubscriptionResource (CRUD, mark_paid action, navigation badge for overdue)
- SuperAdminResource (CRUD, reset password, toggle 2FA, can't self-delete)
- ViewCompany page with live stats (users/clients/vehicles/WO/parts/revenue/
  storage/last_login + days_until_expiry), subscriptions history table,
  config snapshot, action buttons (open/issue invoice/upload logo/suspend)
- CompanyResource: row click → view, openUrlInNewTab action, recordTitleAttribute,
  empty state, view route registered
- PlatformStats widget upgraded: 6 cards (incl. MRR realized this month, overdue
  invoices count, click-through to filtered tables)
- RevenueChart: 12-month MRR line chart
- RecentTenants: latest 8 tenants with click-through
- PendingPayments: pending+overdue invoices table
- Database notifications enabled + Cmd+K global search
- HEAD_END render hook: PWA manifest + theme color + emoji favicon
- /admin-manifest.json route

Seeder:
- Plans aligned with new FEATURE_OPTIONS (kanban/pdf/reports/ai/api/reverb/etc)
- 4 plans: Free / Basic / Pro / Enterprise (with proper limits)
- SuperAdmin gets role='owner'
- Demo subscription for psauto on Pro plan, marked paid this month

app/Filament/Central/Resources/CompanyResource.php

@@ -25,6 +25,15 @@ class CompanyResource extends Resource
 
     protected static ?string $pluralModelLabel = 'companii';
 
+    protected static ?int $navigationSort = 10;
+
+    protected static ?string $recordTitleAttribute = 'name';
+
+    public static function getGloballySearchableAttributes(): array
+    {
+        return ['slug', 'name', 'display_name', 'city', 'phone', 'email'];
+    }
+
     public static function form(Schema $schema): Schema
     {
         return $schema->components([
@@ -123,7 +132,16 @@ class CompanyResource extends Resource
                     'suspended' => 'Suspendat', 'archived' => 'Arhivat',
                 ]),
             ])
+            ->recordUrl(fn (Company $r) => CompanyResource::getUrl('view', ['record' => $r]))
             ->actions([
+                Actions\ViewAction::make()
+                    ->url(fn (Company $r) => CompanyResource::getUrl('view', ['record' => $r])),
+                Actions\Action::make('open_tenant')
+                    ->label('Deschide')
+                    ->icon('heroicon-m-arrow-top-right-on-square')
+                    ->color('primary')
+                    ->url(fn (Company $r) => $r->url('/app'))
+                    ->openUrlInNewTab(),
                 Actions\Action::make('suspend')
                     ->label('Suspendă')
                     ->icon('heroicon-m-no-symbol')
@@ -141,6 +159,9 @@ class CompanyResource extends Resource
                 Actions\EditAction::make(),
                 Actions\DeleteAction::make(),
             ])
+            ->emptyStateHeading('Niciun tenant încă')
+            ->emptyStateDescription('Adaugă primul client SaaS folosind butonul „Adaugă companie" — se va crea un tenant nou cu admin pe `<slug>.service.mir.md/app`.')
+            ->emptyStateIcon('heroicon-o-building-office-2')
             ->defaultSort('created_at', 'desc');
     }
 
@@ -149,6 +170,7 @@ class CompanyResource extends Resource
         return [
             'index' => Pages\ListCompanies::route('/'),
             'create' => Pages\CreateCompany::route('/create'),
+            'view' => Pages\ViewCompany::route('/{record}'),
             'edit' => Pages\EditCompany::route('/{record}/edit'),
         ];
     }