perf(async): remove blocking std::process::Command from async paths

Every production process spawn reachable from a tokio worker now uses
tokio::process: the install path's podman-port probe, the dependencies
disk check, factory-reset restart, config host-IP detection, the
orchestrator's host-facts helpers (resolve_dynamic_env and its call
sites made async to carry it through), and AutoRuntime's podman/docker
probes.

The FIPS transport probe is the special case: is_available() is a sync
trait method called from async route(), so instead of blocking ~50ms
on systemctl per stale-cache hit it now serves the cached value and
refreshes on a background thread (stale-while-revalidate) — bounded
staleness, zero stalled workers.

§C of the 1.8.0 hardening plan; container/transport/config/package
suites green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/archipelago/src/config.rs

@@ -81,10 +81,11 @@ pub struct Config {
 
 impl Config {
     /// Detect primary host IP (first non-loopback IPv4)
-    fn detect_host_ip() -> Result<String> {
-        let output = std::process::Command::new("hostname")
+    async fn detect_host_ip() -> Result<String> {
+        let output = tokio::process::Command::new("hostname")
             .args(["-I"])
             .output()
+            .await
             .context("Failed to run hostname -I")?;
         let s = String::from_utf8_lossy(&output.stdout);
         let ip = s
@@ -210,7 +211,9 @@ impl Config {
         if let Ok(ip) = std::env::var("ARCHIPELAGO_HOST_IP") {
             config.host_ip = ip;
         } else {
-            config.host_ip = Self::detect_host_ip().unwrap_or_else(|_| "127.0.0.1".to_string());
+            config.host_ip = Self::detect_host_ip()
+                .await
+                .unwrap_or_else(|_| "127.0.0.1".to_string());
         }
 
         // Ensure data directory exists