Built-In Skills Should Stay Private in APX

Built-in skills should remain private within the APX runtime, as they are integral to the system's operation and should not be editable like regular user skills. The distinction between built-in skills, project skills, and global user-installed skills is crucial for maintaining the proper functioning of both APC (portable context layer) and APX (daily-use runtime and tooling layer).

APC carries project-specific truth and artifacts, while APX turns that portable contract into live behavior on a single machine. Built-in skills are distinct from these two categories, as they are part of the APX runtime itself and should always be available, active, and outside the normal enable or delete flows. This separation ensures that APC and APX have clearly defined roles and responsibilities.

The policy for built-in skills is already in place, with the APX skills loader scanning three sources in priority order: project skills in the project/.apc/skills/ directory, user-installed global skills in ~/.apx/skills/, and built-in APX skills shipped inside the runtime. This clear delineation of skill origins and policies ensures that APC owns project-portable skills, APX owns machine-local user skills, and built-ins are protected from being disabled or deleted.

Implementing this clear distinction between skill types helps maintain a clean separation between APC and APX, ensuring the runtime is predictable and reliable across different machines and environments.