Optimize shell startup and include demo artwork

README.md

@@ -159,9 +159,9 @@ The shell provides an edge-to-edge libcosmic menu bar backed
 by the private shell-control connection. Build and preview it nested with:
 
 ```bash
-cargo build -p ferese -p ferese-shell
+cargo build --release -p ferese -p ferese-shell
-target/debug/ferese --backend nested --grant-effects --grant-shell-control -- \
+target/release/ferese --backend nested --grant-effects --grant-shell-control -- \
-  target/debug/ferese-shell
+  target/release/ferese-shell
 ```
 
 The Ferese mark enters overview, where workspace indicators become available.
@@ -171,6 +171,12 @@ shadow. Window spacing uses the workspace outer gap; `top_bar_window_gap` under
 `[theme.geometry]` adds optional extra space (default 0). Solid and translucent
 shell surfaces also omit outlines. The dark startup fallback matches the material palette.
 
+The shell decodes wallpaper in parallel with startup and prefers the lightweight
+software renderer, with GPU rendering available as a fallback. Glass effects
+still run on the compositor GPU. Set `ICED_BACKEND=wgpu` to explicitly use GPU
+rendering for shell content. Use release builds when evaluating startup and
+animation performance; debug image processing is considerably slower.
+
 Keyboard and direct-session touchpad settings are applied at startup:
 
 ```toml

shell/ferese-shell/Cargo.toml

@@ -8,8 +8,8 @@ rust-version = "1.93"
 [dependencies]
 ferese-protocols = { path = "../../crates/ferese-protocols", default-features = false, features = ["client"] }
 jiff.workspace = true
-# Wallpaper resampling must not block the bar on iced's shared UI thread.
+# Keep GPU rendering available as a fallback/override. The shell defaults to
-# Keep tiny-skia available as libcosmic's fallback, but prefer GPU rendering.
+# tiny-skia to avoid a second GPU initialization during desktop startup.
 libcosmic = { workspace = true, features = ["wgpu"] }
 serde.workspace = true
 toml.workspace = true

shell/ferese-shell/src/main.rs

@@ -79,6 +79,13 @@ impl From<ShellTheme> for BarMetrics {
 }
 
 fn main() -> cosmic::iced::Result {
+    // Small shell surfaces do not need a second GPU device and shader setup.
+    // Keep wgpu as a fallback and honor an explicit renderer preference.
+    if std::env::var_os("ICED_BACKEND").is_none() {
+        // SAFETY: this is the process entry point, before any worker or
+        // toolkit threads are started.
+        unsafe { std::env::set_var("ICED_BACKEND", "tiny-skia,wgpu") };
+    }
     let config = config::load();
     // Decode alongside toolkit/GPU initialization, never during a UI draw.
     let wallpaper = config.wallpaper.path.clone().map(|path| {
@@ -227,7 +234,8 @@ impl cosmic::Application for FereseShell {
             Some(Box::new(Self::view_layer)),
         );
 
-        let tasks = [wallpaper_action, bar_action]
+        // Submit the small interactive surface before the full-screen image.
+        let tasks = [bar_action, wallpaper_action]
             .map(cosmic::Action::Surface)
             .map(cosmic::task::message);