Replace user configuration with KDL and improve Rust source spacing

shell/ferese-settings/Cargo.toml

@@ -6,10 +6,10 @@ license.workspace = true
 rust-version = "1.93"
 
 [dependencies]
+ferese-config = { path = "../../crates/ferese-config" }
 libcosmic = { workspace = true, features = ["wgpu", "a11y", "xdg-portal"] }
 ferese-ipc = { path = "../../crates/ferese-ipc" }
 serde_json.workspace = true
-toml_edit = "0.25.15"
 tempfile.workspace = true
 shlex = "1.3.0"
 notify = "8.2.0"