refactor: Address review feedback

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

asusd/Cargo.toml

@@ -42,6 +42,7 @@ logind-zbus.workspace = true
 serde.workspace = true
 
 concat-idents.workspace = true
+serde_json = "1.0.149"
 
 [dev-dependencies]
 cargo-husky.workspace = true