fix: restore surrogate default in pyhl binary main()

[danbugs]

Summary

PR #22 moved default_surrogate_count() from the pyhl binary's main() into the library functions (install() and Runtime::new()). However, the binary's cmd_run() calls Sandbox::from_snapshot_file_configured() directly — bypassing both library entry points. This left HYPERLIGHT_INITIAL_SURROGATES unset for pyhl run, causing Hyperlight to pre-spawn all 512 surrogate processes (~3.5s on Windows).

• Make default_surrogate_count() public in the library
• Call it from main() in the binary so both setup and run paths are covered

Benchmark impact

Benchmark	Before (PR #22)	Expected after fix
hello_world (median)	1005 ms	~248 ms
pandas (median)	1678 ms	~757 ms

[github-actions]

Linux Benchmarks

Details

Benchmark suite	Current: 1a15b27	Previous: 8affbcc	Ratio
hello_world (median)	20 ms	20 ms	1
pandas (median)	100 ms	100 ms	1
density (per VM)	7 MB	7 MB	1
snapshot (disk)	384 MiB	384 MiB	1

This comment was automatically generated by workflow using github-action-benchmark.

[github-actions]

Windows Benchmarks

Details

Benchmark suite	Current: 1a15b27	Previous: 8affbcc	Ratio
hello_world (median)	259 ms	899 ms	0.29
pandas (median)	897 ms	1508 ms	0.59
density (per VM)	6 MB	6 MB	1
snapshot (disk)	392 MiB	392 MiB	1

This comment was automatically generated by workflow using github-action-benchmark.