v0.9.7

What's Changed

• Fail new tree creation when layer files exist by @poszu in #414
• Allow running registration service only by @poszu in #417
• Bump golang.org/x/sys from 0.12.0 to 0.13.0 by @dependabot in #420
• Bump golang.org/x/sync from 0.3.0 to 0.4.0 by @dependabot in #421
• Optimize PoW by @poszu in #419

Full Changelog: v0.9.6...v0.9.7