Fix issue where theme would be changed to black and can't be switched back on iOS 18

Removed line which forces preferred colour scheme to dark on iOS 18, and
made adjustments to the styling to maintain text legibility

Changelog-Fixed: Fixed issue where theme would be changed to black and can't be switched back on iOS 18
Closes: https://github.com/damus-io/damus/issues/2373
Co-authored-by: Daniel D’Aquino <daniel@daquino.me>
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>

damus/Components/SupporterBadge.swift

@@ -11,11 +11,13 @@ struct SupporterBadge: View {
     let percent: Int?
     let purple_account: DamusPurple.Account?
     let style: Style
+    let text_color: Color
     
-    init(percent: Int?, purple_account: DamusPurple.Account? = nil, style: Style) {
+    init(percent: Int?, purple_account: DamusPurple.Account? = nil, style: Style, text_color: Color = .secondary) {
         self.percent = percent
         self.purple_account = purple_account
         self.style = style
+        self.text_color = text_color
     }
     
     let size: CGFloat = 17
@@ -31,7 +33,7 @@ struct SupporterBadge: View {
                     if self.style == .full {
                         let date = format_date(date: purple_account.created_at, time_style: .none)
                         Text(date)
-                            .foregroundStyle(.secondary)
+                            .foregroundStyle(text_color)
                             .font(.caption)
                     }
                 }

damus/Views/NoteContentView.swift

@@ -120,8 +120,7 @@ struct NoteContentView: View {
             EventView(damus: damus_state, event: self.event, options: .embedded_text_only)
                 .padding(.top)
         }
-        .background(.thinMaterial)
-        .preferredColorScheme(.dark)
+        .background(.thickMaterial)
         .onTapGesture(perform: {
             damus_state.nav.push(route: Route.Thread(thread: .init(event: self.event, damus_state: damus_state)))
             dismiss()

damus/Views/Purple/DamusPurpleAccountView.swift

@@ -64,7 +64,6 @@ struct DamusPurpleAccountView: View {
                 .padding(.bottom, 20)
             }
             .foregroundColor(.white.opacity(0.8))
-            .preferredColorScheme(.dark)
             .background(.ultraThinMaterial, in: RoundedRectangle(cornerRadius: 12, style: .continuous))
             .padding()
         }
@@ -81,7 +80,8 @@ struct DamusPurpleAccountView: View {
             SupporterBadge(
                 percent: nil,
                 purple_account: account,
-                style: .full
+                style: .full,
+                text_color: .white
             )
         }
     }