SideScreen 0.4.0

SideScreen 0.4 gives Muse Link a persistent helper, eight scoped desktop tools, compact observations, semantic find/wait, and fresh-target action batches. Native UIA properties are cached per inspection; CUA runs over a retained MCP connection. Shared state and installation paths avoid Windows packaged AppData redirection. Health probes report real CUA readiness and require a non-overlapping agent monitor.

The preview targets 10 fps and composites the physical cursor and layered overlays. Capture was checked on the actual SideScreen bounds; deliberate physical cursor movement was not tested.

Validation: 22 non-UI checks, 37 native background checks, 61 native/WPF CUA checks, 12 adapter checks, and 32 end-to-end checks through Muse Link's simulated agent MCP channel. Real fixture state confirmed Unicode, button/checkbox actions and screenshots. Foreground/keyboard focus stayed intact during tested actions. CUA 0.31.0 remains a separate installation. The archive includes only SideScreen tools and documentation, with no CUA binaries, personal configuration or test apps.

A virtual monitor shares the Windows input session. This is not universal isolation. A fresh Playwright extension connection can activate Chrome; Muse Link detects the focus change. No reboot, remote Muse network or ChatGPT backend integration was tested. Read docs/validation.md and docs/cua.md for the tested scope and installation.