unify server, run, simplify utils

# What does this PR do?


## Test Plan
# What does this PR do?


## Test Plan
# What does this PR do?


## Test Plan

llama_stack/cli/utils.py

@@ -0,0 +1,31 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+import argparse
+
+
+def add_config_template_args(parser: argparse.ArgumentParser):
+    """Add unified config/template arguments with backward compatibility."""
+    group = parser.add_mutually_exclusive_group(required=True)
+
+    group.add_argument(
+        "config",
+        nargs="?",
+        help="Configuration file path or template name",
+    )
+
+    # Backward compatibility arguments (deprecated)
+    group.add_argument(
+        "--config",
+        dest="config",
+        help="(DEPRECATED) Use positional argument [config] instead. Configuration file path",
+    )
+
+    group.add_argument(
+        "--template",
+        dest="config",
+        help="(DEPRECATED) Use positional argument [config] instead. Template name",
+    )