Fix reset_stage job to read STAGE_URL from environment

.gitlab-ci.yml

@@ -161,11 +161,16 @@ reset_stage:
       python - <<'RESET_SCRIPT'
       import httpx
       import sys
+      import os
 
-      BASE_URL = "${STAGE_URL}"
+      BASE_URL = os.environ.get("STAGE_URL", "")
       ADMIN_USER = "admin"
       ADMIN_PASS = "changeme123"  # Default admin password
 
+      if not BASE_URL:
+          print("ERROR: STAGE_URL environment variable not set")
+          sys.exit(1)
+
       print(f"=== Resetting stage environment at {BASE_URL} ===")
 
       client = httpx.Client(base_url=BASE_URL, timeout=60.0)