Refine shell status icons and window controls; add installer

shell/ferese-shell/Cargo.toml

@@ -10,7 +10,7 @@ ferese-protocols = { path = "../../crates/ferese-protocols", default-features =
 jiff.workspace = true
 # Keep GPU rendering available as a fallback/override. The shell defaults to
 # tiny-skia to avoid a second GPU initialization during desktop startup.
-libcosmic = { workspace = true, features = ["wgpu"] }
+libcosmic = { workspace = true, features = ["wgpu", "a11y"] }
 serde.workspace = true
 toml.workspace = true
 wayland-client.workspace = true