Support prompt file as positional arg in stage1

prompts/smol_save_config.txt

@@ -0,0 +1,8 @@
+You are a helpful assistant with access to tools.
+
+Available tools:
+- save_config: Save a configuration object. Args: {"config": "object"}
+
+User: Create a detailed configuration for a web server with the following sections: server (host, port, ssl), logging (level, format, outputs), cache (enabled, ttl, max_size), rate_limiting (enabled, requests_per_minute, burst), cors (enabled, origins, methods, headers), security (headers, csp, hsts). Use the save_config tool.
+
+Assistant:

scripts/stage1_debug.py

@@ -12,6 +12,13 @@ from vllm import LLM, SamplingParams
 
 MODEL_PATH = os.environ.get("MODEL_PATH", "/workspace/models/SmolLM3-3B")
 PROMPT_FILE = os.environ.get("PROMPT_FILE", "/workspace/prompts/smol_write_file.txt")
+# Also support passing as first positional arg
+import sys
+if len(sys.argv) > 1 and not sys.argv[1].startswith("-"):
+    if "/" in sys.argv[1]:
+        PROMPT_FILE = sys.argv[1]
+    else:
+        PROMPT_FILE = f"/workspace/prompts/{sys.argv[1]}"
 MAX_TOKENS = int(os.environ.get("MAX_TOKENS", "512"))
 TEMPERATURE = float(os.environ.get("TEMPERATURE", "0.0"))