Document the complete first-package rollout

[Llewellynvdm]

The first-package instructions left plugin release preparation implicit. This records the exact Actions workflows and their order, with the missing webservices trigger supplied by joomengine/mcp_webservices#2 and console metadata/installed-CI corrections in joomengine/mcp_plugin#3.

Run each plugin's version/update-feed/OctoShoom workflow first. Then run the component workflow: it alone invokes OctoJPack, publishes to mcp_package, updates the package feed and runs OctoShoom. No package workflow or secrets are needed in mcp_package.

The instructions explain secret scope, valid first versions (0.1.2 is one unused example), later plugin-tag reuse and workflow_dispatch rather than tag-push triggering. Both changelogs and agent guidance record the completed release contract.

Documentation only: component code, workflows and .octojpack remain unchanged.

Validation on a5d2745:

• PHP contracts: https://github.com/joomengine/mcp_component/actions/runs/36452852732 — passed.
• Installed Joomla, all four PHP/database combinations: https://github.com/joomengine/mcp_component/actions/runs/36452852892 — passed.
• Installed JCB golden image: https://github.com/joomengine/mcp_component/actions/runs/36452852764 — passed.
• The actual metadata from all three source repositories was prepared successfully in temporary copies for example version 0.1.2, producing each plugin's own tagged download and the combined package download in the component feed. XML and whitespace checks pass.

Merge the companion PRs, configure the documented repository secrets, then run console, webservices and component releases in that order. No release tag or package is published by this PR.