fix: Respect app's user interface style override

[rcaos]

Hey guys, I'm working on an app that doesn't support dark mode yet (I know, it's a shame 😅). I ran into some issues when activating the debugger, and this PR solves that problem.

Summary

Respect host app's user interface style override when determining dark mode state in UserInterfaceToolkit to prevent forced dark mode in apps that explicitly disable it.

Problem

When a UIKit app explicitly overrides overrideUserInterfaceStyle to .light (e.g., in AppDelegate), DebugSwift still applies dark mode to its interface. This causes visual issues where all views appear black/incorrect because the library's dark mode theming conflicts with the host app's light-only configuration.

Root Cause

• UserInterfaceToolkit.swift was checking UIScreen.main.traitCollection.userInterfaceStyle to determine dark mode state
• This system-level check returns the device's dark mode preference, ignoring any app-specific overrides
• Apps that explicitly set overrideUserInterfaceStyle to disable dark mode support were having their preference bypassed
• This creates visual inconsistencies and broken UI when DebugSwift applies dark theming to light-mode-only apps

Solution

Check the actual window's trait collection first before falling back to the system preference. The window's trait collection respects app-level overrideUserInterfaceStyle settings, ensuring DebugSwift adapts to the host app's configuration. This approach maintains compatibility with all integration scenarios:

• UIKit apps with explicit light/dark mode overrides
• UIKit apps that follow system appearance
• SwiftUI apps

Changes

• Modified dark mode detection in UserInterfaceToolkit.swift:100-109
• Now checks UIWindow.keyWindow?.traitCollection.userInterfaceStyle first (respects app overrides)
• Falls back to UIScreen.main.traitCollection.userInterfaceStyle if no window is available yet (system preference)