Fix Poke webhook payload format

Poke API expects {"message": "..."}, not a complex structure.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/models/notification_models.py

@@ -38,23 +38,12 @@ class EmailNotificationPayload(BaseModel):
 
     def to_webhook_format(self) -> dict:
         """Convert to the format expected by Poke webhook."""
-        return {
-            "type": self.event_type,
-            "timestamp": self.timestamp.isoformat(),
-            "data": {
-                "id": self.email_id,
-                "mailbox": self.mailbox,
-                "message_id": self.message_id,
-                "from": {
-                    "email": self.from_email,
-                    "name": self.from_name,
-                },
-                "to": self.to_emails,
-                "subject": self.subject,
-                "snippet": self.snippet,
-                "date": self.date.isoformat(),
-                "has_attachments": self.has_attachments,
-                "is_flagged": self.is_flagged,
-                "in_reply_to": self.in_reply_to,
-            }
-        }
+        # Format sender
+        sender = self.from_name if self.from_name else self.from_email
+
+        # Build message
+        message = f"New email from {sender}\nSubject: {self.subject}"
+        if self.snippet:
+            message += f"\n\n{self.snippet}"
+
+        return {"message": message}