L11 Kundenversand: Bericht-PDF an Kunden senden (Service, Action, API, Berichtsseite)

- sendReportToCustomer: report:approve, Scope, nur approved mit PDF, Empfänger
  Ansprechpartner -> Kunde, Dedupe je Adresse+Version, Audit export
- Server Action + POST /api/v1/reports/{id}/send inkl. OpenAPI-Eintrag
- /reports/[id]: Abschnitt „An Kunden senden" mit bisherigen Versänden, Texte de/en

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

messages/en/reports.json

@@ -226,6 +226,37 @@
     "alreadySigned": "Signature captured.",
     "noReport": "Create the completion report first."
   },
+  "customerMail": {
+    "title": "Send to customer",
+    "sub": "The approved PDF is sent to the customer as an attachment. Replies go to your company's reply address.",
+    "to": "Recipient",
+    "toHint": "Prefilled with the work order contact or the customer.",
+    "noDefault": "No e-mail address is stored for this work order. Please enter a recipient.",
+    "message": "Message (optional)",
+    "messagePlaceholder": "Short message to the customer",
+    "submit": "Send report",
+    "sending": "Sending …",
+    "history": "Previous sends",
+    "historyEmpty": "Not sent to the customer yet.",
+    "result": {
+      "sent": "Report sent to {to}.",
+      "queued": "Report to {to} is being sent.",
+      "duplicate": "This version has already been sent to {to}.",
+      "failed": "Sending to {to} failed. Please try again later."
+    },
+    "delivery": {
+      "sent": "Sent",
+      "pending": "Being delivered",
+      "failed": "Failed",
+      "other": "Not delivered"
+    },
+    "errors": {
+      "recipient_missing": "Please enter an e-mail address.",
+      "invalid_to": "Please enter a valid e-mail address.",
+      "report_not_approved": "Only approved reports can be sent.",
+      "pdf_missing": "The PDF has not been generated yet."
+    }
+  },
   "pdf": {
     "page": "Page {page} of {pages}",
     "reportId": "Report ID",