Demo plan + Payment integrations (Stripe/PayPal/Bank)

Models & migrations:
- platform_settings table (key/value JSON store + Cache::remember 5min)
- plans: is_demo bool + trial_days int
- companies: is_demo bool

Plans:
- Demo plan seeded (is_demo=true, is_public=false, all features, 14 trial days)
- Trial 14-day plan seeded (is_public=true, basic features)
- Plan form: is_demo toggle + trial_days field
- Plan table: badge 🎬 Demo / 🎁 N zile trial

Central panel:
- PaymentSettings page (heroicon-credit-card, sort 90)
  Form sections: General, Date legale, Stripe, PayPal, Transfer bancar
  Each gateway collapsible, fields hidden until enabled toggle
  Saves to platform_settings keyed by `payments.{gateway}`
- CompanyResource: is_demo toggle + table description

Payment flow (PaymentController):
- GET  /billing                 — tenant invoices list with Pay button
- POST /pay/{sub}               — start checkout (stripe/paypal/bank)
- GET  /pay/{sub}/{success,cancel}
- POST /payments/stripe/webhook — mark paid + extend company.active_until
- POST /payments/paypal/webhook — same

Views:
- site/billing.blade.php       — invoices list with payment modal (3 methods)
- site/bank-instructions       — IBAN/BIC/reference for manual transfer
- site/checkout-stub           — placeholder until composer require stripe-php
- site/payment-{success,cancel}

Tenant panel:
- userMenuItems → "Facturile mele" link to /billing

routes/web.php

@@ -24,6 +24,26 @@ Route::get('/', function () {
     return redirect('/admin');
 });
 
+// ─── Plăți / Billing (tenant-side) ──────────────────────────────────
+// /billing — listă facturi tenant + buton plată
+// /pay/{id} — start checkout (Stripe / PayPal / bank)
+Route::get('/billing', [\App\Http\Controllers\PaymentController::class, 'billing'])->name('billing');
+Route::post('/pay/{subscription}', [\App\Http\Controllers\PaymentController::class, 'startCheckout'])
+    ->where('subscription', '\d+')
+    ->name('pay.start');
+Route::get('/pay/{subscription}/success', [\App\Http\Controllers\PaymentController::class, 'success'])
+    ->where('subscription', '\d+')
+    ->name('pay.success');
+Route::get('/pay/{subscription}/cancel', [\App\Http\Controllers\PaymentController::class, 'cancel'])
+    ->where('subscription', '\d+')
+    ->name('pay.cancel');
+
+// ─── Webhooks (central, no auth) ────────────────────────────────────
+Route::post('/payments/stripe/webhook', [\App\Http\Controllers\PaymentController::class, 'stripeWebhook'])
+    ->withoutMiddleware([\Illuminate\Foundation\Http\Middleware\VerifyCsrfToken::class]);
+Route::post('/payments/paypal/webhook', [\App\Http\Controllers\PaymentController::class, 'paypalWebhook'])
+    ->withoutMiddleware([\Illuminate\Foundation\Http\Middleware\VerifyCsrfToken::class]);
+
 // Stub `login` route — needed because Laravel's auth middleware tries to
 // route('login') when redirecting unauthenticated requests. We don't have a
 // global /login (panels use /admin/login and /app/login), so stub it.