docs: add usage, trademark and security disclaimer (#18)

Author: opensource-SantanderAI

README.md

@@ -137,6 +137,14 @@ Please report vulnerabilities privately as described in
 [`.github/SECURITY.md`](.github/SECURITY.md). Do **not** open public issues for
 security reports.
 
+## Disclaimer
+
+This software is an open source project from the **Santander AI Lab**, provided **"as is"** under its [license](LICENSE), without warranties or conditions of any kind. It is **not an official Banco Santander product or service**, carries no commitment of production support, and does not constitute financial, legal or professional advice.
+
+"Santander" and its logo are registered trademarks of **Banco Santander, S.A.** The project license does not grant any right to use them beyond factual attribution.
+
+If you believe you have found a security vulnerability, follow our [security policy](https://github.com/SantanderAI/.github/blob/main/SECURITY.md) — do not open a public issue. You are responsible for assessing the suitability of this software for your use case and for keeping your own deployments up to date.
+
 ## License
 
 Licensed under the [Apache License 2.0](LICENSE). See [`NOTICE`](NOTICE) for