feat(obs): integrate dial9-tokio-telemetry for runtime tracing (#2285)

Co-authored-by: heihutu <heihutu@gmail.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: houseme <4829346+houseme@users.noreply.github.com>

crates/obs/examples/test_dial9.rs

@@ -0,0 +1,53 @@
+// Test dial9 integration example
+use rustfs_obs::dial9::{Dial9Config, is_enabled};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("=== Dial9 Integration Test ===\n");
+
+    // Test 1: Check initial dial9 state
+    println!("Test 1: Default state");
+    let initial_enabled = is_enabled();
+    println!("  dial9 enabled: {}", initial_enabled);
+    if initial_enabled {
+        println!("  ⚠ SKIP: Dial9 is already enabled via environment; skipping default-disabled assertion\n");
+    } else {
+        println!("  ✓ PASS: Dial9 is disabled by default\n");
+    }
+
+    // Test 2: Load default configuration
+    println!("Test 2: Default configuration");
+    let config = Dial9Config::from_env();
+    println!("  enabled: {}", config.enabled);
+    println!("  output_dir: {}", config.output_dir);
+    println!("  file_prefix: {}", config.file_prefix);
+    println!("  max_file_size: {} bytes", config.max_file_size);
+    println!("  rotation_count: {}", config.rotation_count);
+    println!("  s3_bucket: {:?}", config.s3_bucket);
+    println!("  s3_prefix: {:?}", config.s3_prefix);
+    println!("  sampling_rate: {}", config.sampling_rate);
+    println!("  ✓ PASS: Default configuration loaded\n");
+
+    // Test 3: Configuration validation
+    println!("Test 3: Configuration validation");
+    if !initial_enabled {
+        assert!(!config.enabled, "Should be disabled by default");
+        assert_eq!(config.s3_bucket, None, "S3 bucket should be None by default");
+        assert_eq!(config.s3_prefix, None, "S3 prefix should be None by default");
+        println!("  ✓ PASS: Configuration validated\n");
+    } else {
+        println!("  ⚠ SKIP: Configuration validation skipped (dial9 is enabled)\n");
+    }
+
+    println!("=== All Tests Passed! ===");
+    println!();
+    println!("Note: To test with dial9 enabled, set environment variables:");
+    println!("  export RUSTFS_RUNTIME_DIAL9_ENABLED=true");
+    println!("  export RUSTFS_RUNTIME_DIAL9_OUTPUT_DIR=/tmp/rustfs-test-telemetry");
+    println!("  export RUSTFS_RUNTIME_DIAL9_SAMPLING_RATE=0.5");
+    println!("  export RUSTFS_RUNTIME_DIAL9_S3_BUCKET=my-bucket");
+    println!("  export RUSTFS_RUNTIME_DIAL9_S3_PREFIX=telemetry/");
+    println!("  cargo run -p rustfs-obs --example test_dial9");
+
+    Ok(())
+}