Hardened Java 21+ Development Container for AI Agents

// src/main/java/dev/App.java · Java 21 LTS Pattern Matching
public sealed interface Task permits Query, Mutation {
    record Query(String id, Instant timestamp) implements Task {}
    record Mutation(String id, byte[] payload) implements Task {}

    static String describe(Task t) {
        return switch (t) {
            case Query(var id, var ts) -> "Query " + id;
            case Mutation(var id, _)   -> "Mutation " + id;
        };
    }
}