The lease simulator must distinguish a current owner from an older client whose lease expired. Implement ownership and renewal with the specified fencing-token behavior.
Build the implementation in Rust 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 is an ordered list of events with nondecreasing integer time, op acquire/release, and owner string. Acquire has positive integer ttl; grant only if no active lease, returning a new token starting at 1, otherwise null. A lease expires when time >= expiry. Release includes integer token and returns true only for the current owner/token while active; stale releases return false. Return one token/null/boolean per event. Invalid operations, times, ttl or tokens must be rejected.
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.