fix(discord): propagate role_authorized flag so DISCORD_ALLOWED_ROLES works end-to-end

DISCORD_ALLOWED_ROLES was checked by the Discord adapter (_is_allowed_user)
but gateway._is_user_authorized only read DISCORD_ALLOWED_USERS, so
role-authorized users were rejected with "Unauthorized user" at the
gateway layer despite passing the adapter gate.

- Add role_authorized: bool = False to SessionSource
- Add role_authorized param to build_source (base.py)
- Compute _role_authorized in on_message when user passes via role not user ID
- Thread _role_authorized through _handle_message -> build_source
- Check source.role_authorized early in _is_user_authorized (run.py)

Fixes #33952

plugins/platforms/discord/adapter.py

@@ -794,6 +794,7 @@ class DiscordAdapter(BasePlatformAdapter):
                 # Must run BEFORE the user allowlist check so that bots
                 # permitted by DISCORD_ALLOW_BOTS are not rejected for
                 # not being in DISCORD_ALLOWED_USERS (fixes #4466).
+                _role_authorized = False
                 if getattr(message.author, "bot", False):
                     allow_bots = os.getenv("DISCORD_ALLOW_BOTS", "none").lower().strip()
                     if allow_bots == "none":
@@ -817,6 +818,7 @@ class DiscordAdapter(BasePlatformAdapter):
                         is_dm=_is_dm,
                     ):
                         return
+                    _role_authorized = bool(getattr(self, "_allowed_role_ids", set()))
                 
                 # Multi-agent filtering: if the message mentions specific bots
                 # but NOT this bot, the sender is talking to another agent —
@@ -858,7 +860,7 @@ class DiscordAdapter(BasePlatformAdapter):
                         if "*" not in _free_channels and not (_channel_ids & _free_channels):
                             return
 
-                await self._handle_message(message)
+                await self._handle_message(message, role_authorized=_role_authorized)
 
             @self._client.event
             async def on_voice_state_update(member, before, after):
@@ -4726,7 +4728,7 @@ class DiscordAdapter(BasePlatformAdapter):
                     raise Exception(f"HTTP {resp.status}")
                 return await resp.read()
 
-    async def _handle_message(self, message: DiscordMessage) -> None:
+    async def _handle_message(self, message: DiscordMessage, role_authorized: bool = False) -> None:
         """Handle incoming Discord messages."""
         # In server channels (not DMs), require the bot to be @mentioned
         # UNLESS the channel is in the free-response list or the message is
@@ -4910,6 +4912,7 @@ class DiscordAdapter(BasePlatformAdapter):
             guild_id=str(guild.id) if guild else None,
             parent_chat_id=parent_channel_id,
             message_id=str(message.id),
+            role_authorized=role_authorized,
         )
 
         # Build media URLs -- download image attachments to local cache so the