perf(api): eliminate expensive heap allocations and memory clones by serializing axum response payloads directly from store read locks

server/Cargo.toml

@@ -39,3 +39,8 @@ tempfile = "3.27.0"
 [[bin]]
 name = "test_rmcp"
 path = "src/bin_test.rs"
+
+[[bin]]
+name = "bin_test_axum"
+path = "src/bin_test_axum.rs"
+