Fix 500 when exiting hosting panel for existing accounts.

The account overview queried a local mailboxes table that the extracted hosting app does not have; guard those lookups and skip email-addon upsells when mailboxes are managed on Ladill Email.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Models/HostingAccount.php

@@ -3,6 +3,7 @@
 namespace App\Models;
 
 use Carbon\CarbonInterface;
+use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Model;
@@ -10,6 +11,7 @@ use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\Relations\HasOne;
 use Illuminate\Database\Eloquent\SoftDeletes;
+use Illuminate\Support\Facades\Schema;
 
 class HostingAccount extends Model
 {
@@ -159,6 +161,28 @@ class HostingAccount extends Model
         return $this->hasMany(Mailbox::class, 'hosting_account_id');
     }
 
+    /** The extracted hosting app does not store mailboxes locally — they live on Ladill Email. */
+    public static function tracksLocalMailboxes(): bool
+    {
+        static $hasTable = null;
+
+        return $hasTable ??= Schema::hasTable('mailboxes');
+    }
+
+    /** @return Collection<int, Mailbox> */
+    public function loadedMailboxes(): Collection
+    {
+        if (! static::tracksLocalMailboxes()) {
+            return new Collection;
+        }
+
+        if (! $this->relationLoaded('mailboxes')) {
+            $this->load('mailboxes');
+        }
+
+        return $this->mailboxes;
+    }
+
     public function billingInvoices(): HasMany
     {
         return $this->hasMany(HostingBillingInvoice::class, 'hosting_account_id');
@@ -268,9 +292,11 @@ class HostingAccount extends Model
 
     public function paidMailboxCount(): int
     {
-        return $this->relationLoaded('mailboxes')
-            ? $this->mailboxes->where('is_paid', true)->count()
-            : $this->mailboxes()->where('is_paid', true)->count();
+        if (! static::tracksLocalMailboxes()) {
+            return 0;
+        }
+
+        return $this->loadedMailboxes()->where('is_paid', true)->count();
     }
 
     public function renew(?int $durationMonths = null, array $metadata = []): void