CLI: add --help to print usage and env-based configuration hints

run.py

@@ -1,6 +1,7 @@
 import asyncio
 import os
 import logging
+import sys
 
 from server.server import GameServer
 from server.config import ServerConfig
@@ -70,6 +71,14 @@ async def run_webtransport():
 
 if __name__ == "__main__":
     try:
+        if any(a in ("-h", "--help") for a in sys.argv[1:]):
+            print(
+                "Usage: python run.py [--mode mem|quic|wt] [--log-level LEVEL] [--run-seconds N]\n"
+                "  TLS (for wt/quic): set QUIC_CERT/QUIC_KEY or WT_CERT/WT_KEY env vars\n"
+                "  WT static server (MODE=wt): STATIC=1 [STATIC_HOST/PORT/ROOT]\n"
+                "Examples:\n  MODE=wt QUIC_CERT=cert.pem QUIC_KEY=key.pem python run.py\n  MODE=mem python run.py"
+            )
+            sys.exit(0)
         # Logging setup
         level = os.environ.get("LOG_LEVEL", "INFO").upper()
         logging.basicConfig(level=getattr(logging, level, logging.INFO), format="[%(asctime)s] %(levelname)s: %(message)s")