refactor: Simplify default_labels function to use HashMap::from

- Replace the manual creation of a HashMap in the default_labels function with a more concise HashMap::from method.
- Update the default labels to include specific keys for blackbox project, environment, and instance.

Author: incubator4

src/config.rs

@@ -20,9 +20,11 @@ pub struct Target {
 }
 
 fn default_labels() -> HashMap<String, String> {
-    let mut labels = HashMap::new();
-    labels.insert("default".to_string(), "true".to_string());
-    labels
+    HashMap::from([
+        ("blackbox/project".to_string(), "default".to_string()),
+        ("blackbox/env".to_string(), "default".to_string()),
+        ("blackbox/instance".to_string(), "default".to_string()),
+    ])
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone)]