Downgrade Docusaurus to 3.4.0 for Node 18 compatibility

[Agentscreator]

This PR addresses Node 18 compatibility issues and resolves multiple security vulnerabilities in the website dependencies.

Changes Made
Downgrade Docusaurus to 3.4.0 - Ensures compatibility with Node 18 (the project's minimum required version)

Updated @docusaurus/core from latest to 3.4.0
Updated @docusaurus/preset-classic to 3.4.0
Updated dev dependencies accordingly
Security Updates - Added dependency overrides to fix known vulnerabilities:

undici: Updated to ^6.23.0
ajv: Updated to ^8.18.0
minimatch: Updated to ^10.2.4

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