feat(runner): add structured logging with tracing

- Add tracing, tracing-subscriber, uuid dependencies
- Replace eprintln! with info! for structured logs
- Add run_id, rust_version, os, arch to benchmark start log

runner/build.rs

@@ -0,0 +1,16 @@
+use std::{env, process::Command};
+
+fn main() {
+    let rustc_version = env::var("RUSTC_VERSION").unwrap_or_else(|_| {
+        Command::new("rustc")
+            .arg("--version")
+            .output()
+            .ok()
+            .and_then(|output| String::from_utf8(output.stdout).ok())
+            .unwrap_or_else(|| "unknown".to_string())
+            .trim()
+            .to_string()
+    });
+
+    println!("cargo:rustc-env=RUSTC_VERSION={rustc_version}");
+}