fix(modmail): correct attachment handling + include initial message in transcript

- Fix discord.File.from_attachment (nonexistent) -> Attachment.to_file()
- Record initial ticket reason into transcript history

commandes/modmail.py

@@ -105,6 +105,18 @@ class TicketModal(discord.ui.Modal, title="Nouveau Ticket"):
 
         await _send_ticket_panel(ticket_channel, interaction.user, self.category_name, self.reason.value)
 
+        cog = interaction.client.get_cog("ModMail")
+        if cog is not None:
+            cog._dm_messages.setdefault(interaction.user.id, []).append(
+                {
+                    "author": interaction.user,
+                    "content": self.reason.value,
+                    "timestamp": discord.utils.utcnow(),
+                    "attachments": [],
+                    "is_staff": False,
+                }
+            )
+
         with contextlib.suppress(discord.HTTPException):
             await interaction.followup.send(
                 f"Ticket cree: {ticket_channel.mention}",
@@ -520,7 +532,7 @@ class ModMail(commands.Cog):
         await channel.send(embed=embed)
 
         for att in message.attachments:
-            await channel.send(file=await discord.File.from_attachment(att))
+            await channel.send(file=await att.to_file())
 
     # --- COMMANDES ---