Fix widget systemSmall preview

[bgoncal]

Summary

Screenshots

Link to pull request in Documentation repository

Documentation: home-assistant/companion.home-assistant#

Any other notes

[Copilot]

Pull request overview

This PR refines widget layout handling by wiring the WidgetFamily into SwiftUI previews and the widget creation UI, and updates snapshots for the systemSmall “withoutSubtitleWithIconBackground” configuration.

Changes:

• Added WidgetKit import and @Environment(\.widgetFamily) usage support in WidgetBasicView, and propagated explicit widgetFamily values through various previews.
• Introduced a (problematic) custom EnvironmentKey/EnvironmentValues pair for WidgetFamily and used it in widget previews and the widget creation view.
• Regenerated snapshot PNGs for the systemSmall “withoutSubtitleWithIconBackground” widget in light and dark modes.

Reviewed changes

Copilot reviewed 3 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
Tests/Widgets/Snapshots/WidgetsSnapshot.test/systemSmallSnapshots.withoutSubtitleWithIconBackground-systemSmall-02_tiles-light.png	Updated light-mode snapshot for the systemSmall widget without subtitle and with icon background to match the new layout.
Tests/Widgets/Snapshots/WidgetsSnapshot.test/systemSmallSnapshots.withoutSubtitleWithIconBackground-systemSmall-02_tiles-dark.png	Updated dark-mode snapshot for the same widget configuration to reflect the revised rendering.
Sources/Extensions/Widgets/Common/WidgetBasicView.swift	Imports WidgetKit so the view can use @Environment(\.widgetFamily) and adjust layout (e.g., spacing/height) based on the widget family.
Sources/Extensions/Widgets/Common/WidgetBasicContainerView.swift	Adds a retroactive EnvironmentKey conformance on WidgetFamily, defines a widgetFamily environment value, and sets it in widget previews for different WidgetFamily sizes.
Sources/App/Settings/Widgets/Builder/WidgetCreationView.swift	Injects a widgetFamily environment value into the widget preview used in the widget creation UI so WidgetBasicView can size itself correctly.