Broaden the paper evaluation beyond sequential simulation paths

[maloleroy]

Motivation

The manuscript compares Aer state vectors and MQT DDSIM on a fixed sequential path. Reviewers may reasonably ask about alternative Aer methods, DDSIM simulation paths, larger standard workloads, and multiple machines.

Acceptance criteria

• Add at least one path-optimized DD configuration or explain API limitations
• Add representative non-contrived circuits beyond the current small QASMBench subset
• Separate kernel time from process startup for every engine where possible
• Repeat on a second machine or archived CI runner profile
• Preserve raw failures, hashes, package versions, and resource limits
• Update threats to validity and the manuscript without overstating generality

This is valuable for a full conference submission but not required for the current reproducible manuscript milestone.