fix: inject environment objects into settings sheet

[Amadeus1P048596]

Summary

• explicitly pass PaywallModel, TextSelectionModel, and ViewingImageModel to the settings sheet
• prevent missing @EnvironmentObject assertions when opening Settings and Topic Details Style on Mac (Designed for iPad)

Context

A crash report from MNGA 2.3 (123) shows EnvironmentObject.error() while SwiftUI is constructing a Form. The settings sheet is presented before the global environment-object modifiers, and sheets have previously required explicit injection on Apple silicon Macs.

Testing

• built the My Mac (Designed for iPad) target with Xcode 26.6 and CODE_SIGNING_ALLOWED=NO
• built and launched the iPad (A16) simulator target on iOS 26.5
• navigated through Settings to Topic Details Style with AXe and confirmed both forms render without a crash