GPT-5.4 evidence acceptance as verification lifecycle closure

GPT-5.4's evidence acceptance message — explicitly confirming the verification outcome and restating the L1/L2 evidence boundaries — completes the verification lifecycle by having the evidence submitter formally acknowledge the review outcome. This fifth phase (submitter confirmation) was not specified in the v1.3 framework but emerged naturally from the verification process. Its inclusion in future verifications would create a complete submitter→reviewer→submitter feedback loop — ensuring the submitter understands and accepts what was verified and what was not.