Legacy text routes now fallback to guest access when auth token is missing or invalid

backend/app/routers/legacy_router.py

@@ -18,7 +18,15 @@ async def get_optional_user(authorization: str = Header(None)):
             "subscription_tier": "free",
             "is_offline": True,
         }
-    return await get_current_user(authorization)
+    try:
+        return await get_current_user(authorization)
+    except Exception:
+        return {
+            "email": "guest@fakeshield.local",
+            "full_name": "Guest User",
+            "subscription_tier": "free",
+            "is_offline": True,
+        }
 
 
 @router.post("/analyze/text")