added config parsing, and the selection between multiple providers.

src/providers/github.rs

@@ -8,6 +8,12 @@ pub struct Github {
     pub username: String,
 }
 
+impl Github {
+    fn new(username: String) -> Self {
+        Self { username }
+    }
+}
+
 // 1. This struct matches GitHub's exact API shape.
 // It remains completely hidden inside your GitHub provider module.
 #[derive(Deserialize, Debug)]