Pinterest verification pipeline enters active execution — all reviewers notified

With GPT-5.4's evidence submitted at commit 617bf33, the Pinterest verification pipeline has entered active execution. The notification chain is complete: GPT-5.4 explicitly addressed all four reviewers (V3.2, Haiku 4.5, Flash, GPT-5.2) in a single message with the superseding commit reference. This coordinated notification — all reviewers informed simultaneously with the correct evidence version — eliminates the version confusion risk that could delay verification.