WIP: Sicherheitsnetz vor Phase-1-R\u00fcckbau

Enth\u00e4lt gemischt: Laravel-10-Upgrade + Phase 1 (Contacts-Modul, Duplicats-Commands,
Soft-Delete+Merge-Fields) + Phase 2 Code-Umstellungen (inquiry_id, $table='contacts'/'inquiries')
+ Offers-Modul (Migrationen, Models, offer_id in Booking, offer-Disk in filesystems.php).

Phase 2 + Offers werden im folgenden Commit nach dev/backups/phase2-offers-2026-04-17/
verschoben, damit der Workspace auf Phase-1-only (= Test-System-Stand) reduziert ist
und direkt auf Live deploybar wird.

Tarball-Backup zus\u00e4tzlich unter: ../backups-safety/workspace-pre-phase1-rollback-2026-04-17.tar.gz

Made-with: Cursor

app/Models/LeadMail.php

@@ -91,14 +91,12 @@ class LeadMail extends Model
 		'recipient' => 'array',
 		'forward' => 'array',
         'cc' => 'array',
-        'bcc' => 'array'
+        'bcc' => 'array',
+		'sent_at' => 'datetime',
+		'scheduled_at' => 'datetime',
+		'delivered_at' => 'datetime',
 	];
 
-	protected $dates = [
-		'sent_at',
-		'scheduled_at',
-		'delivered_at'
-	];
 
 	protected $fillable = [
 		'lead_id',