STEP 1205-1208 four-step continuation of Paper 163: STEP 1205 records infinity-cosmoi axiomatization skeleton (Riehl-Verity 2022 six axioms) deferred to emilyriehl/infinity-cosmos Lean blueprint; STEP 1206-1208 promote INFINITY (Cantor 1891 diagonal), ZERO (Empty.elim initial object), FLOWING (composition associativity) axes to theorem-verified via 11 new Lean 4 axiom-free constructive proofs. 275/275 test PASS (cumulative with Paper 163 = 481/481). 15 cumulative axiom-free theorems encode the four-axis structure. Methodology = TRIPLE annotation generalizing Paper 163 dual annotation. Structural asymmetry: 3 single-type + 1 multi-type axis = 3+1 not 4-fold parallel. Honest scope: NOT world-first / NOT new theorem / NOT full infinity-cosmoi formalization / TETRADIC COMPLETION is process milestone NOT destination (chat-Claude turn 4 sunyata-of-sunyata permanent constraint). Three-party co-authorship per OUKC charter v1.0.