Add centered workspace thumbnails to overview

Render a tinted, scrollable workspace strip with live thumbnails, output-scaled font labels and a subtle selected-workspace outline. Keep the window grid background-free and support workspace selection without exiting overview.

Animate strip opacity independently with precise fade tolerances and continuous reversal, and expose toggle-overview through feresectl.

compositor/src/main.rs

@@ -72,6 +72,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         viewport_spring_config: config.viewport_spring_config()?,
         output_profiles,
         wallpaper: config.wallpaper_settings(),
+        overview_font_family: config.overview_font_family(),
     };
     let mut state = Ferese::new(&mut event_loop, display, runtime)?;
     backends::init(launch.backend, &mut event_loop, &mut state)?;