Prepare v0.2.0 release

[yvette-carlisle]

Summary

• bump the workspace and internal rsnap crates to 0.2.0
• update the native-host fallback app version for release bundle builds
• update release-facing docs from v0.1.7 to v0.2.0 while preserving the current scroll-capture exposure notes

Verification

• cargo make checks
• cargo make test-host-reset
• cargo make test-macos-native-host-stage
• scripts/perf/macos.sh
• docs path reference check: all docs/*.md references resolve
• release preflight: no local or remote v0.2.0 tag existed before this PR