feat(session): add durable session archival

packages/protocol/src/groups/session.ts

@@ -269,6 +269,21 @@ export const makeSessionGroup = <I extends HttpApiMiddleware.AnyId, S>(sessionLo
           }),
         ),
     )
+    .add(
+      HttpApiEndpoint.post("session.archive", "/api/session/:sessionID/archive", {
+        params: { sessionID: Session.ID },
+        success: HttpApiSchema.NoContent,
+        error: SessionNotFoundError,
+      })
+        .middleware(sessionLocationMiddleware)
+        .annotateMerge(
+          OpenApi.annotations({
+            identifier: "v2.session.archive",
+            summary: "Archive session",
+            description: "Archive a session.",
+          }),
+        ),
+    )
     .add(
       HttpApiEndpoint.post("session.move", "/api/session/:sessionID/move", {
         params: { sessionID: Session.ID },