refactor(network): finish script compression

[LucaLin233]

Summary

• compact managed-state staging and restore rollback paths
• consolidate health delta classification and status section rendering
• deduplicate argument validation, RTT selection, trap restoration, and route snapshots
• preserve existing initcwnd hook directory permissions during atomic writes
• reduce modules/network-optimize.sh from 3252 to 3099 lines

Validation

• bash -n modules/network-optimize.sh
• shellcheck --severity=warning modules/network-optimize.sh
• full repository ShellCheck at CI error severity
• bash tests/run.sh
• forwarding and RA management keyword scan