set TSSBOT presence to "Soon..." (#1232)

Adds a custom-activity status in on_ready so the bot reads
"Soon..." in the member list until the real feature set lands.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

start_bot.py

@@ -43,6 +43,9 @@ bot = commands.Bot(command_prefix="!", intents=intents)
 async def on_ready():
     log.info(f"logged in as {bot.user} (id={bot.user.id if bot.user else '?'})")
     log.info(f"connected to {len(bot.guilds)} guild(s)")
+    await bot.change_presence(
+        activity=discord.CustomActivity(name="Soon...")
+    )
 
 
 if __name__ == "__main__":