ci(dogfood): replace plumb.aramhammoudeh.com acceptance with an honest path

[aram-devdocs]

After #227's revert removed the docs/plumb.toml ignore hack, dogfood exits 3 daily. PRD §15 says 0 violations clean. Three paths: (A) lint a landing page we author, (B) customize mdBook theme to use plumb tokens, (C) revise §15 to 'exit 0 or 3 + deterministic.' Recommend (C) for V0.