fix: satisfy clippy on docker gateway routing PR

[mjamiv]

Summary

• stack on fix(docker): harden supervisor startup and gateway routing #1128 to unblock the Rust lint jobs
• remove two unnecessary std::path::Path qualifications reported by unused_qualifications
• box the run_from_args future at the gateway CLI entrypoint to satisfy clippy::large_futures

Test

• cargo fmt --all -- --check
• cargo clippy -p openshell-sandbox --all-targets -- -D warnings
• cargo clippy -p openshell-server --all-targets -- -D warnings

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