refactor(auth): remove keys auth module and align tests

- remove server auth module and client keys page/routes/api to simplify flow

- update mcp and scenario tests to match uuid routes and step schema

server/test/session.controller.spec.ts

@@ -141,7 +141,7 @@ describe("SessionController", () => {
     });
 
     it("returns 404 for unknown id", async () => {
-      await request(app.getHttpServer()).delete("/sessions/99999").expect(404);
+      await request(app.getHttpServer()).delete("/sessions/00000000-0000-0000-0000-000000000001").expect(404);
     });
 
     it("returns 400 for non-numeric id", async () => {