admin api: new router_v2 with unified path syntax

src/api/admin/mod.rs

@@ -4,21 +4,28 @@ mod error;
 pub mod api;
 mod router_v0;
 mod router_v1;
+mod router_v2;
 
 mod bucket;
 mod cluster;
 mod key;
+mod special;
 
 use std::sync::Arc;
 
 use async_trait::async_trait;
-use serde::Serialize;
 
 use garage_model::garage::Garage;
 
+pub enum Authorization {
+	None,
+	MetricsToken,
+	AdminToken,
+}
+
 #[async_trait]
 pub trait EndpointHandler {
-	type Response: Serialize;
+	type Response;
 
 	async fn handle(self, garage: &Arc<Garage>) -> Result<Self::Response, error::Error>;
 }