docs: codify ac-os oven as the canonical OTA path
ac-os upload is a local-build fallback that stashes uncommitted work in
ways that can strand changes outside fedac/native/ (its cleanup
git-checkout is scoped to that subdir). The remote oven flow is what
ships releases.aesthetic.computer/os/ under normal operation.
Surfaced in CLAUDE.md and fedac/native/SCORE.md so agents land on
ac-os oven before reaching for upload.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>