feat: add lz4hc archive compression

[loks0n]

Syncs the SDK with the orchestrator API changes since the last update (2026-08-21).

Summary

• Add ArchiveCompression::Lz4hc — mirrors orchestrator #76 (lz4hc for tar/squashfs) and #77 (lz4/lz4hc for erofs, which also enables fragments + dedupe server-side)
• JobsTest's erofs archive artifact now exercises the new case

Not needed

• Clone artifact, mount sync/syncIntervalSeconds, and sandbox shape read-back are already on main
• The new durationSeconds field on orchestrator.job.artifact callback events (orchestrator #82) flows through the untyped CloudEvent::$data array, so no SDK change is required

Test plan

• composer test (34 tests), composer analyze, composer format:check, composer refactor:check — all pass

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

Adds ArchiveCompression::Lz4hc to align the PHP SDK with the orchestrator’s expanded archive compression support.

• Serializes the new compression option as lz4hc.
• Updates the Jobs request test to exercise LZ4HC compression with an EROFS archive.

Confidence Score: 5/5

The PR appears safe to merge with no actionable correctness, security, or compatibility issues identified.

The new enum case flows through the existing generic enum-value serialization path, and the updated Jobs test verifies the exact orchestrator wire value.

Important Files Changed

Filename	Overview
src/Enum/ArchiveCompression.php	Adds the correctly valued Lz4hc backed-enum case, which existing generic artifact serialization handles without further mapping changes.
tests/JobsTest.php	Updates a reachable Jobs request fixture and expected payload to verify EROFS archives serialize LZ4HC compression as lz4hc.

_{Reviews (1): Last reviewed commit: "feat: add lz4hc archive compression" | Re-trigger Greptile}