fix: Client.start() takes no log_handler kwarg (run()-only)

log_handler belongs to Client.run() (which configures logging and then
calls start()); passing it to start() raised TypeError at launch. This was
inherited from the never-run dockerised variant's thin_client.py. We
configure our own handlers, so simply drop the kwarg.

Also set logger.propagate=False: a dependency calls logging.basicConfig(),
so every 'discord' record was printed twice (our format + root's).

Verified with a strict-signature stub client (start(token, *, reconnect)).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

bot.py

@@ -62,6 +62,9 @@ console_handler = logging.StreamHandler()
 console_handler.setLevel(logging.INFO)
 console_handler.setFormatter(formatter)
 logger.addHandler(console_handler)
+# Some dependency calls logging.basicConfig(), adding a root handler; without
+# this the 'discord' logger's records get printed twice (our format + root's).
+logger.propagate = False
 
 # *=========================================== Initializations
 intents = discord.Intents.default()
@@ -238,7 +241,10 @@ async def _run_bot(token: str, shutdown_event: asyncio.Event) -> None:
     docker). Now every death is diagnosed on the console first.
     """
     try:
-        await client.start(token, log_handler=None)
+        # NOTE: log_handler is a Client.run()-only kwarg (run() configures
+        # logging, then calls start()); start() takes just the token. We set
+        # up our own handlers above, so nothing is lost.
+        await client.start(token)
     except discord.LoginFailure:
         logger.critical(
             "FATAL: Discord REJECTED the token (Improper token). Fix the "