Stage 15 — PWA complete: install prompt + Web Push notifications

Dependency:
- minishlink/web-push v10 (VAPID JWT + aes128gcm payload encryption)
- Dockerfile: add curl, mbstring, gmp extensions (web-push needs ext-curl)

VAPID:
- config/webpush.php from env; `php artisan push:vapid` generates keypair
- Shared platform keypair; .env.example has empty placeholders

Schema:
- push_subscriptions (user/company, endpoint unique, p256dh, auth, encoding)

WebPushService:
- send / sendToUser / dispatch via WebPush::flush
- Auto-prunes subscriptions reported expired (404/410)

Subscribe flow:
- POST /push/subscribe + /push/unsubscribe (auth, tenant)
- Tenant panel JS subscribes after SW registration with VAPID public key

Service worker (/sw.js):
- Cache v2, push listener → showNotification, notificationclick → focus/open

Install prompt:
- Floating "Instalează aplicația" button wired to beforeinstallprompt

Staff push:
- WorkOrder master_id change → push to assigned mechanic
- Settings "Test notificare push" action

Tests (6 new):
- subscribe stores + upserts; requires auth (401); validation (422);
  service configured; sendToUser with no subs returns zero

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/Models/Tenant/WorkOrder.php

@@ -141,6 +141,21 @@ class WorkOrder extends Model implements HasMedia
                 app(\App\Services\NotificationDispatcher::class)->workOrderReady($wo);
             }
 
+            // Push the assigned mechanic when a WO gets assigned to them.
+            if ($wo->wasChanged('master_id') && $wo->master_id) {
+                try {
+                    app(\App\Services\Notifications\WebPushService::class)->sendToUser(
+                        (int) $wo->master_id,
+                        'Fișă nouă atribuită',
+                        "Fișa #{$wo->number} · " . ($wo->vehicle?->plate ?? ''),
+                        '/app/resources/work-orders/' . $wo->id . '/edit',
+                        'wo-assign-' . $wo->id,
+                    );
+                } catch (\Throwable $e) {
+                    \Illuminate\Support\Facades\Log::debug('WO assign push skipped: ' . $e->getMessage());
+                }
+            }
+
             // Warehouse lifecycle: status=done → consume reservations into issues;
             // status=cancelled → release reservations.
             if ($wo->wasChanged('status')) {