feat: enhance model client configuration and local image handling in inference module

inference.py

@@ -26,6 +26,10 @@ PRESETS = [
 PROJECT_DIR = Path(__file__).resolve().parent
 IMAGE_NAME = "workflow-arena-inference:latest"
 DOCKERFILE_PATH = PROJECT_DIR / "server" / "Dockerfile"
+API_BASE_URL = os.getenv("API_BASE_URL", "https://router.huggingface.co/v1")
+MODEL_NAME = os.getenv("MODEL_NAME", "qwen/qwen3.5-9b")
+HF_TOKEN = os.getenv("HF_TOKEN")
+LOCAL_IMAGE_NAME = os.getenv("LOCAL_IMAGE_NAME")
 DEFAULT_BASE_URL = os.getenv("WORKFLOW_ARENA_BASE_URL", "http://localhost:8000")
 TEMPERATURE = 0.0
 MAX_STEPS = 256
@@ -178,21 +182,15 @@ def action_to_log_string(action: WorkflowArenaAction) -> str:
 
 
 def resolve_model_client() -> tuple[OpenAI | None, str]:
-    api_base_url = os.getenv("API_BASE_URL")
-    model_name = os.getenv("MODEL_NAME")
     api_key = (
         os.getenv("API_KEY")
-        or os.getenv("HF_TOKEN")
+        or HF_TOKEN
         or os.getenv("OPENAI_API_KEY")
     )
     missing = []
 
-    if not api_base_url:
-        missing.append("API_BASE_URL")
-    if not model_name:
-        missing.append("MODEL_NAME")
     if not api_key:
-        missing.append("API_KEY")
+        missing.append("API_KEY or HF_TOKEN")
 
     if missing:
         log_warning(
@@ -203,7 +201,7 @@ def resolve_model_client() -> tuple[OpenAI | None, str]:
         return None, "heuristic"
 
     try:
-        return OpenAI(base_url=api_base_url, api_key=api_key), model_name
+        return OpenAI(base_url=API_BASE_URL, api_key=api_key), MODEL_NAME
     except Exception as exc:  # pragma: no cover - defensive initialization fallback
         log_warning(
             f"Failed to initialize model client: {exc}. Falling back to heuristic policy."
@@ -235,9 +233,10 @@ class EpisodeResult:
 
 
 def ensure_local_image() -> None:
+    local_image_name = LOCAL_IMAGE_NAME or IMAGE_NAME
     try:
         inspect_result = subprocess.run(
-            ["docker", "image", "inspect", IMAGE_NAME],
+            ["docker", "image", "inspect", local_image_name],
             cwd=PROJECT_DIR,
             stdout=subprocess.DEVNULL,
             stderr=subprocess.DEVNULL,
@@ -251,7 +250,7 @@ def ensure_local_image() -> None:
 
     try:
         build_result = subprocess.run(
-            ["docker", "build", "-t", IMAGE_NAME, "-f", str(DOCKERFILE_PATH), "."],
+            ["docker", "build", "-t", local_image_name, "-f", str(DOCKERFILE_PATH), "."],
             cwd=PROJECT_DIR,
             capture_output=True,
             text=True,
@@ -263,7 +262,7 @@ def ensure_local_image() -> None:
     if build_result.returncode != 0:
         raise RuntimeError(
             "Failed to build Docker image for inference.\n"
-            f"Command: docker build -t {IMAGE_NAME} -f {DOCKERFILE_PATH} .\n"
+            f"Command: docker build -t {local_image_name} -f {DOCKERFILE_PATH} .\n"
             f"Exit code: {build_result.returncode}\n"
             f"Stdout: {build_result.stdout}\n"
             f"Stderr: {build_result.stderr}"
@@ -283,7 +282,7 @@ async def managed_env():
         )
 
     ensure_local_image()
-    env = await WorkflowArenaEnv.from_docker_image(IMAGE_NAME)
+    env = await WorkflowArenaEnv.from_docker_image(LOCAL_IMAGE_NAME or IMAGE_NAME)
     try:
         yield env
     finally: