Update branding

Update the Ferese symbols, appearance-specific wallpapers, and rounded wallpaper and theme previews. Bundle Figtree and add the Ferese name to the website header.

Verified configuration, theme, Settings, wallpaper and installer tests, both UI renderers, the static site build, and browser layouts.

shell/ferese-settings/src/pages.rs

@@ -179,30 +179,13 @@ impl App {
             }
 
             if self.page == Page::Wallpaper {
-                if let Some(handle) = &self.thumbnail {
-                    body = body.push(
-                        widget::image(handle.clone())
-                            .width(Length::Fill)
-                            .height(160)
-                            .content_fit(cosmic::iced::ContentFit::Contain),
-                    );
-                } else {
-                    body = body.push(self.note(if self.thumbnail_loading {
-                        "Loading wallpaper preview…"
-                    } else {
-                        self.thumbnail_error
-                            .as_deref()
-                            .unwrap_or("Choose an image to preview your wallpaper.")
-                    }));
-                }
-                body = body.push(self.settings_button(
-                    "Choose image…",
-                    "M3 4h18v16H3z M3 15l5-5 5 5 3-3 5 5 M15 8h.01",
-                    Some(Message::PickWallpaper),
-                    false,
-                ));
+                body = body.push(self.wallpaper_controls());
             }
-            let fields = schema::fields(self.page);
+            let fields = if self.page == Page::Wallpaper {
+                self.wallpaper_fields()
+            } else {
+                schema::fields(self.page)
+            };
 
             if !fields.is_empty() {
                 let mut group = column([]).spacing(1);