refactor(obs): migrate metrics runtime/schema and tighten migration guards (#2584)

crates/obs/src/metrics/mod.rs

@@ -0,0 +1,25 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+pub mod collectors;
+pub mod config;
+pub mod report;
+pub mod scheduler;
+pub mod schema;
+pub mod stats_collector;
+
+pub use collectors::*;
+pub use config::*;
+pub use report::{PrometheusMetric, report_metrics};
+pub use scheduler::{init_metrics_collectors, init_metrics_runtime};