IceHrm VPS Deployment with PKI

I have a freshly provisioned Linux VPS and I want IceHrm up and running on it—secured, optimised and ready for daily use. Once the core installation is live, the key requirement is to enable advanced digital signing through a PKI workflow so every contract, payslip or approval generated in IceHrm can be signed and later verified. Here’s what I need from you: • Install and configure the complete IceHrm stack on the VPS (web server, PHP, database) and secure it over HTTPS. • Integrate PKI-based signing: the system must call the CA, embed the signature in each generated document and let administrators verify it from the interface. • Keep the integration upgrade-safe so future IceHrm updates won’t wipe the custom code. • Deliver concise documentation covering setup steps, how to add new user certificates and how to audit signatures. • Prove success with a short test plan: I should be able to generate a sample PDF in IceHrm, sign it using the supplied certificate and verify the signature with any standard PKI tool. Root SSH access to the VPS and existing server certificates will be supplied after award. Let me know which tools or libraries you plan to rely on—OpenSSL, phpseclib, external CA APIs, etc.—and your expected turnaround time.