Enabling a build feature can pull in other features and introduce a conflict. Finish the feature resolver so it reports the full enabled set and identifies incompatible selections before the build starts.
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 has requires mapping feature names to required features, requested names and conflicts as pairs of known features. Enable the transitive requirement closure, allowing cycles. Return sorted enabled names and sorted unique conflict pairs (each pair sorted) whose two members are enabled. Reject any unknown feature in requests, requirements or conflicts.
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.