Learning Lab for Jenkins IaC/CaC

It would be very helpful to have a learning lab that walks through how to containerize Jenkins and set it up so that the instance comes up preconfigured using:

**Plugin Installation:** installed during container build time
**Jenkins Server Configs:** configured using Jenkins Configuration as Code (JCasC)
**Job Configurations:** Created using Job DSL and invoked from the JCasC file
**Everything Else:** for things that can’t be easily configured using Job DSL or JCasC, use System Groovy Scripts invoked from JCasC

This learning lab should show how to take the upstream Jenkins community image and customize it for use with SDP:

1. Show how to manually configure a Jenkins instance (plugin installs, instance configs, job configs)
2. Show how to automate that manual configuration by extending the community container image with the strategies outlined above

No files, tests, or entry points are named. Start by reviewing the upstream Jenkins community image and the manual configuration steps described in the issue, then map plugin installation, server settings, jobs, and remaining configuration to the proposed mechanisms. Done means a learning lab demonstrates both manual setup and the automated, preconfigured container workflow for SDP.

Written by the indexing model from the issue text.