Requests should not be accepted with an expired or already-used nonce. Finish the replay window so expiry and duplicate detection use the supplied logical time consistently.
Build the implementation in Go under /app, with /app/run.sh as its entry point. Read one JSON request from standard input and write one JSON result to standard output. Input has positive integer ttl and requests with key string, nonce string and nondecreasing integer time. A (key,nonce) accepted at t remains reserved until t+ttl exclusive. Repeat requests before expiry are rejected without extending it; a request exactly at expiry is accepted again. Return accepted booleans. Reject invalid ttl or decreasing request time. This is an offline policy simulation, not an authentication implementation.
Reject inputs that violate an explicit validation rule with exit status 2, no standard output, and {"error":"invalid_input"} on standard error. For valid input, exit with status 0. Keep the implementation reusable for new inputs; it must work offline and must not depend on the example data being the only data it receives.
Repair or replace the unfinished /app/run.sh and add source files under /app. Malformed JSON must use the same invalid-input response. Do not read /tests or /oracle from the application.