added runtime/env check and api key check

src/utils/runtime_selector.py

@@ -0,0 +1,14 @@
+import platform
+import GPUtil
+from dotenv import load_dotenv
+load_dotenv()
+
+def detect_runtime_environment():
+    os_type = platform.system().lower()
+    gpus = GPUtil.getGPUs()
+    if gpus:
+        return "gpu"
+    elif os_type in ["darwin", "linux"]:
+        return "cpu-local"
+    else:
+        return "cloud-only"