feat(obs): unify metrics initialization and fix exporter move error (#851)

* feat(obs): unify metrics initialization and fix exporter move error

- Fix Rust E0382 (use after move) by removing duplicate MetricExporter consumption.
- Consolidate MeterProvider construction into single Recorder builder path.
- Remove redundant Recorder::builder(...).install_global() call.
- Ensure PeriodicReader setup is performed only once (HTTP + optional stdout).
- Set global meter provider and metrics recorder exactly once.
- Preserve existing behavior for stdout/file vs HTTP modes.
- Minor cleanup: consistent resource reuse and interval handling.

* update telemetry.rs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix

* fix

* fix

* fix: modify logger level from error to event

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

rustfs/src/server/audit.rs

@@ -26,7 +26,7 @@ use tracing::{error, info, warn};
 pub(crate) async fn start_audit_system() -> AuditResult<()> {
     info!(
         target: "rustfs::main::start_audit_system",
-        "Step 1: Initializing the audit system..."
+        "Initializing the audit system..."
     );
 
     // 1. Get the global configuration loaded by ecstore
@@ -39,7 +39,7 @@ pub(crate) async fn start_audit_system() -> AuditResult<()> {
             config.clone()
         }
         None => {
-            error!(
+            warn!(
                 target: "rustfs::main::start_audit_system",
                 "Audit system initialization failed: Global server configuration not loaded."
             );

rustfs/src/server/event.rs

@@ -14,7 +14,7 @@
 
 use rustfs_config::DEFAULT_DELIMITER;
 use rustfs_ecstore::config::GLOBAL_SERVER_CONFIG;
-use tracing::{error, info, instrument};
+use tracing::{error, info, instrument, warn};
 
 /// Shuts down the event notifier system gracefully
 pub(crate) async fn shutdown_event_notifier() {
@@ -28,7 +28,7 @@ pub(crate) async fn shutdown_event_notifier() {
     let system = match rustfs_notify::notification_system() {
         Some(sys) => sys,
         None => {
-            error!("Event notifier system is not initialized.");
+            info!("Event notifier system is not initialized.");
             return;
         }
     };
@@ -49,7 +49,7 @@ pub(crate) async fn init_event_notifier() {
     let server_config = match GLOBAL_SERVER_CONFIG.get() {
         Some(config) => config.clone(), // Clone the config to pass ownership
         None => {
-            error!("Event notifier initialization failed: Global server config not loaded.");
+            warn!("Event notifier initialization failed: Global server config not loaded.");
             return;
         }
     };