[router] add --log-level to sgl-router (#6512)

sgl-router/py_src/sglang_router/router.py

@@ -31,8 +31,8 @@ class Router:
             routing. Default: 60
         max_payload_size: Maximum payload size in bytes. Default: 256MB
         max_tree_size: Maximum size of the approximation tree for cache-aware routing. Default: 2^24
-        verbose: Enable verbose logging. Default: False
         log_dir: Directory to store log files. If None, logs are only output to console. Default: None
+        log_level: Logging level. Options: 'debug', 'info', 'warning', 'error', 'critical'.
         service_discovery: Enable Kubernetes service discovery. When enabled, the router will
             automatically discover worker pods based on the selector. Default: False
         selector: Dictionary mapping of label keys to values for Kubernetes pod selection.
@@ -66,8 +66,8 @@ class Router:
         eviction_interval_secs: int = 60,
         max_tree_size: int = 2**24,
         max_payload_size: int = 256 * 1024 * 1024,  # 256MB
-        verbose: bool = False,
         log_dir: Optional[str] = None,
+        log_level: Optional[str] = None,
         service_discovery: bool = False,
         selector: Dict[str, str] = None,
         service_discovery_port: int = 80,
@@ -100,8 +100,8 @@ class Router:
             eviction_interval_secs=eviction_interval_secs,
             max_tree_size=max_tree_size,
             max_payload_size=max_payload_size,
-            verbose=verbose,
             log_dir=log_dir,
+            log_level=log_level,
             service_discovery=service_discovery,
             selector=selector,
             service_discovery_port=service_discovery_port,