Windows surface split

Two independent Windows integrations. Do not mix them in one code path.

Surface	Transport	UI	Package
Widgets Board	widget_data.json keys ac:template:{id} / ac:data:{id} + pending_actions	Adaptive Cards via C# IWidgetProvider	MSIX App Extension com.microsoft.windows.widgets
Desktop wallpaper (WorkerW)	Existing desktop webview / widget.html	Frameless Tauri webview HWND reparented under WorkerW	No MSIX widget extension; feature workerw

Widgets Board

• Transpile: Rust to_adaptive_card (+ rasterize chart/canvas/gauge → PNG data URI)
• Host write: desktop::set_widget_config on cfg(windows)
• Provider: templates/windows-widget/WidgetProvider
• Init: npx tauri-plugin-widgets-api init-windows
• Preview / goldens: templates/windows-widget/PreviewHost → tests/golden/windows/ (record on Windows VM via just record-windows <case>)
• Adaptive Card JSON snapshots: tests/snapshots/adaptive/ (pnpm -C scripts cli gen-adaptive-snapshots)

WorkerW wallpaper

• Feature flag: workerw (default off)
• API: tauri_plugin_widgets::windows::workerw::{find_workerw, attach_to_workerw}
• Attach after creating a frameless desktop widget window; pass its HWND
• Compile-check via cargo xwin check --features workerw
• Runtime smoke only on an interactive Windows desktop session (tools/win/workerw-smoke.ps1 optional)

UTM tooling

Command	Role
just win-up	SSH healthcheck
just win-bootstrap	Install VS Build Tools / WinAppSDK via PS
just win-sync	Sync repo to C:\work\tauri-plugin-widgets
just test-windows-remote	shot.ps1 smoke
just test-windows-visual / record-windows	PreviewHost PNG
just win-pack / win-sideload	Publish + sideload helpers
just check-windows-xwin	Cross-check plugin
just build-windows-example-xwin	Cross-build demo app