Added MAC Core plugin bootstrap and service kernel

Property	Value
description	Added the OOP plugin bootstrap, constants, autoloading, and central service boot flow.
version	1.0.0
type	Create
related	MAC Core

• Added the minimal plugin bootstrap that loads constants, autoloading, and the central kernel boot flow.
• Kept the plugin architecture namespaced under MacCore instead of using a child-theme-style procedural structure.
• Added the central service-kernel pattern so admin, licensing, settings, and policy services register from one boot path.
• Kept shared pure helpers in the utility layer instead of registering them as hook services.