Prepare v0.2.2 release

[yvette-carlisle]

Summary

• bump Rsnap workspace packages and lockfile to 0.2.2
• update release/docs wording for the v0.2.2 Scroll Capture exposure contract
• document that scroll toolbar Liquid Glass cadence/performance metrics are excluded from the v0.2.2 publish gate and tracked separately

Validation

• cargo make checks
• cargo make test-host-reset
• cargo make test-macos-native-host-stage
• cargo metadata --locked --no-deps --format-version 1
• semantic drift audit reviewed with explicit performance-gate waiver

Known follow-up

• Scroll toolbar Liquid Glass cadence/performance smoke remains a separate follow-up and is intentionally not blocking this release.