README ontology: no README links an archived pre-monorepo repo; pv-validated #5382

Every README.md in the monorepo must describe the monorepo as it is now. Measured 2026-10-15 08:3xZ: 15 of 84 crate READMEs link archived pre-monorepo repos (github.com/paiml//actions badges, crates.io/crates/, docs.rs/). Worst: aprender-serve (11), aprender-orchestrate (11), aprender-train (10), aprender-compute (9), aprender-registry (4).

crates.io renders each crate README at publish time, so this must merge before the 0.72 publish.

Scope:

• pv check that flags README links to archived repos (contract in contracts/ with must-flag / must-pass case table + RED-turning mutation)
• rewrite every README (root + crates/*) to github.com/paiml/aprender, crates.io/docs.rs of the real [package] name, aprender CI badges, derived numbers
• wire the check as a gate (readme_contract.rs), proven silent on the fixed tree first

Refs #3269 (ONT-001)