Make patina_boot and patina_sre platform-neutral for vendor reuse

[kat-perez]

Goal

Make patina_boot and patina_sre platform-neutral so OEMs and vendors can technically adopt the crates without Maa-specific assumptions.

Completion criteria

• Audit the crates for Maa- or vendor-specific configuration, dependencies, and behavior.
• Move platform-specific integration behind an appropriate platform boundary or configuration surface.
• Verify that the public crates build and can be integrated without Maa-specific code paths.
• Document remaining platform requirements and follow-up work.

Related work

• Re-integrate patina_boot and patina_sre on Maa after repository publication #157 re-integrates both crates on Maa now that the repository is public.