v0.7.0 — k(3,4) = 21: a previously unknown Erdos-problem value, determined and certified

Determines k(3,4) = r(I_3,L_4) = 21 (Erdos Problem #112; published bounds were 9 <= k(3,4) <= 25): explicit 20-vertex witness + 346-case LRAT-certified exhaustion at N=21, completeness audited, 445 certificates, ~1.02e9 checked proof steps, every certificate replayed by an independent stdlib checker. Clean-room reproducible: the from-definition CNF generator ships. Also 29 <= k(6,3) <= 33 (lower bound new, separately refereed). Review logs: k34-paper/FIXLOG.md, REFEREE-k63.md; sweeps: SWEEP-RECORD-K34-2026-08-11.md. Paper: k34-paper/note.pdf