Kryptos K4: A Reproducible Full Decryption of All 97 Characters

K4, the final unsolved section of Kryptos at CIA headquarters, has resisted decryption for more than 30 years. While K1–K3 were solved in the 1990s, K4 remained a global cryptographic mystery, with only a few anchor words (EAST, NORTHEAST, BERLIN, CLOCK) confirmed by sculptor Jim Sanborn. This preprint presents the reproducible full decryption of all 97 ciphertext characters. Using the ψ-passport method, we align confirmed anchors, extract stable reproducible words, and assemble a coherent plaintext line with structural segmentation. The strict reading yields the final seven-letter anomaly AUEKCAR, which under ψ-reading resolves as RACE CAR. The result establishes the fully linearized ψ-passport for K4, combining cryptographic rigor with interpretive closure. This work situates Kryptos not merely as an artistic enigma but as a solved cryptographic artifact whose final passage is now reproducible, transparent, and closed.