docs(readme): add new-api as a sponsor

Add the open-source AI infrastructure project new-api as the latest
sponsor entry, appended to the end of the sponsor table across all four
localized READMEs (en/zh/ja/de). Includes the banner asset.

README.md

@@ -179,6 +179,11 @@ TeamoRouter also offers enterprise features including centralized billing, team
 <td>Thanks to <a href="https://nekocode.ai?aff=CCSWITCH">NekoCode</a> for sponsoring this project! NekoCode provides developers with a stable, efficient, and reliable API relay service for Claude, Codex, and other AI models. With transparent pricing and flexible pay-as-you-go billing, it offers a simple and cost-effective way to access AI models. CC Switch users can enjoy an exclusive 10% discount: register via <a href="https://nekocode.ai?aff=CCSWITCH">this link</a> and enter promo code <code>cc-switch</code> during recharge to receive 10% off your top-up!</td>
 </tr>
 
+<tr>
+<td width="180"><a href="https://www.newapi.ai/"><img src="assets/partners/logos/newapi-banner.png" alt="new-api" width="150"></a></td>
+<td>Thanks to the open-source AI infrastructure project <a href="https://www.newapi.ai/">new-api</a> for its strong support of this project! new-api is an open-source AI infrastructure project from QuantumNous and one of the leading unified LLM access-and-distribution projects by activity and adoption, focused on helping developers, teams, and enterprises build manageable, scalable AI service platforms at lower cost. As a fellow project rooted in the open-source ecosystem, new-api hopes to sponsor and support the continued growth of more outstanding open-source projects. 🌟 Star new-api to show your support: <a href="https://github.com/QuantumNous/new-api">https://github.com/QuantumNous/new-api</a>. Website: <a href="https://www.newapi.ai/">https://www.newapi.ai/</a>.</td>
+</tr>
+
 </table>
 
 </details>