Fix share extension theme not updating on system appearance change

[jsj]

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  • iPhone 15 Pro, iOS 17

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Description

When the share extension is open and the user changes the system appearance (dark/light mode) via Control Center or Settings, the share extension UI does not update to reflect the new theme.

Root cause: The Theme.shareExtensionThemeOverride property was only being set once during viewDidLoad, but there was no mechanism to detect and respond to system appearance changes while the share extension was already visible.

Fix: Added traitCollectionDidChange override in ConversationPickerViewController to detect when userInterfaceStyle changes and update Theme.shareExtensionThemeOverride accordingly, which triggers the theme notification and updates the UI.

Testing: Opened share extension from Photos app, toggled dark/light mode via Control Center while share sheet was visible, verified UI updates correctly.

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[sashaweiss-signal]

Thanks for reporting! I'll work on getting this merged internally, and will comment here once that's done.

[sashaweiss-signal]

Thanks again for the contribution! I've merged this internally as 2f3c6b1 (preserving the attribution from your original commit), which will become public with an upcoming release.

Thanks again, and as always for being a Signal user.