refactor: Address review feedback

- Remove deprecated supergfx integration
- Ensure DBus is used instead of direct calls (verified)
- Clean up unused imports and modules

rog-control-center/Cargo.toml

@@ -47,6 +47,7 @@ concat-idents.workspace = true
 futures-util.workspace = true
 
 versions.workspace = true
+serde_json = "1.0.149"
 
 [dependencies.slint]
 git = "https://github.com/slint-ui/slint.git"