refactor(workspace): enforce layered crate boundaries

crates/aether-provider/pool/src/providers/default.rs

@@ -0,0 +1,10 @@
+use crate::provider::ProviderPoolAdapter;
+
+#[derive(Debug, Clone, Default)]
+pub struct DefaultProviderPoolAdapter;
+
+impl ProviderPoolAdapter for DefaultProviderPoolAdapter {
+    fn provider_type(&self) -> &'static str {
+        "default"
+    }
+}