Add OMP provider support

Add OMP (Oh My Pi) as a provider target for Impeccable, so users of https://github.com/can1357/oh-my-pi can install and update the skill through the generated provider output.

Expected work:

• add OMP provider metadata and generated skill output
• wire CLI install/update path handling for OMP
• add test coverage for build and install behavior

Validation planned:

• bun run build
• bun test
• OMP provider smoke check