Arkhe-timechain: a federated verification stack for AI agents — Rust identity layer (ML-DSA-65, VLIB, EIT), TLA+ consensus layer (BFT, CHSH oracle, Proof-of-Entanglement), and Lean 4 physics layer (Bell bound, no sorry), distributed as Ubuntu 2.0 with client-side WASM verification, Kani harnesses, and a falsifiable epistemic ledger that marks every claim as THEOREM, LEMMA, CONJECTURE, or LIMIT.