v0.1.20 - Capacity Audit Cohort Sampling

This release improves hot-capacity audit scheduling by making capped audit cohorts fairer and more scalable for production rollout.

Highlights

• Improved capped hot-capacity cohort sampling so validators select from eligible audit slots more fairly.
• Preserved scalable miner-local selection behavior without requiring miners to scan the network.
• Kept miner version unchanged; validator/spec version is now 0.1.20.

Operator Notes

• Validators auto-update from 0.1.19 to 0.1.20.
• Miners are not forced to auto-update by this release.

Full Changelog: v0.1.19...v0.1.21