refactor(core): Improve code readability and structure

- Format code uniformly, applying consistent indentation and spacing
- Restructure enum, function, and match-case formatting for clarity
- Remove redundant `defaults` from CI workflows

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - name: default (native-tls)
+          - name: default
             features: ""
             no-default-features: false
     steps: