log GSB key presence at startup (no secret value)

app.py

@@ -47,6 +47,12 @@ print("Loading SHAP explainer...")
 explainer = SmishingExplainer(predictor)
 print("Model loaded. Ready.")
 
+# Presence check only — never prints the key itself.
+from utils.safe_browsing import get_checker as _gsb
+
+print(f"GSB key configured: {bool(os.getenv('GOOGLE_SAFE_BROWSING_API_KEY'))} "
+      f"| fallback domains: {len(_gsb().fallback_legit_domains)}")
+
 # ─────────────────────────────────────────────────────────────────────────────
 #  Design system
 # ─────────────────────────────────────────────────────────────────────────────