feat: "Email sent" column and per-event copy-to-organizer BCC

Organizers had no way to see whether a ticket email went out short of
reading the Postfix journal, and no copy of what the attendee received —
LNbits submits over SMTP, so nothing lands in a Sent folder.

- Admin ticket table gains an "Email sent" column derived from
  `extra.email_notification_sent` ("✓ sent" / "not sent" / "unpaid" /
  "no email").
- `extra.copy_to_organizer`: BCC every ticket email to the event's
  reply-to address (explicit, else the owner's account email) on the SMTP
  envelope only — no Bcc/To header, and skipped when the buyer *is* that
  address. Toggle sits with the other delivery switches in the admin form.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EYwoAkZZmXMMmaBp4WGUBo

tests/test_ticket_email.py

@@ -1,5 +1,6 @@
 from datetime import datetime, timezone
 
+import pytest
 from lnbits.settings import settings
 
 from ..models import Event, Ticket
@@ -143,3 +144,33 @@ def test_blank_reply_to_email_is_none():
     assert EventExtra(reply_to_email="").reply_to_email is None
     assert EventExtra(reply_to_email="  ").reply_to_email is None
     assert EventExtra(reply_to_email="a@b.example").reply_to_email == "a@b.example"
+
+
+@pytest.mark.asyncio
+async def test_copy_to_organizer_is_bcc_on_the_envelope_only(monkeypatch):
+    from .. import services
+
+    monkeypatch.setattr(settings, "lnbits_email_notifications_enabled", True)
+    monkeypatch.setattr(
+        settings, "lnbits_email_notifications_email", "oyez@example.org"
+    )
+    monkeypatch.setattr(
+        settings, "lnbits_email_notifications_server", "smtp.example.org"
+    )
+    monkeypatch.setattr(settings, "lnbits_email_notifications_port", 587)
+    monkeypatch.setattr(settings, "lnbits_email_notifications_username", "")
+    monkeypatch.setattr(settings, "lnbits_email_notifications_password", "x")
+    sent = {}
+
+    def fake_smtp_send(
+        server, port, username, password, from_email, recipients, payload
+    ):
+        sent.update(recipients=recipients, payload=payload)
+
+    monkeypatch.setattr(services, "_smtp_send", fake_smtp_send)
+    await services._send_ticket_email_notification(
+        ["buyer@example.com"], "text", "Subj", None, bcc=["organizer@example.org"]
+    )
+    assert sent["recipients"] == ["buyer@example.com", "organizer@example.org"]
+    assert "organizer@example.org" not in sent["payload"]  # no Bcc/To leak
+    assert "To: buyer@example.com" in sent["payload"]