HashCloak zk-ink application

Add application from Elastic Labs for Polkadot Agent Kit (#2549)

Update index.md

Add Polkadot Agent Kit

Author: Mikerah

applications/index.md

@@ -61,6 +61,7 @@ Besides, **there is a clear difference between an application being accepted and
 | [NP Labs](https://np.engineering/)             | [Nullifier Prime: Compliant and Programmable Privacy](./np-compliant_and_programmable_privacy.md)       | [GitHub](https://github.com/NP-Eng) |    ☐       |       ☐       |     ☐      |
 | [Jake Hemmerle](https://github.com/jakehemmerle)             | [Substrate MCP Server](./mcp-polkadot.md)       | [GitHub](https://github.com/jakehemmerle) |    ☐       |       ☐       |     ☐      |
 | [Esscrypt Ltd.](https://esscrypt.com/)             | [Polkadot ElizaOS Plugin](./ElizaPluginPolkadot.md)       | [GitHub](https://github.com/Esscrypt) |    ☐       |       ☐       |     ☐      |
+| [Elastic Labs](https://elasticlabs.org/)             | [Polkadot Agent Kit](./polkadot_agent_kit.md)       | [GitHub](https://github.com/elasticlabs-org/polkadot-agent-kit) |    ☐       |       ☐       |     ☐      |
 
 
 [🔝](#top)