style(box): cargo fmt + fix clippy::single-match in restore readiness

The v2.1.0 snapshot-fork work landed on a feature branch; box ci.yml (fmt +
clippy -D warnings) only runs on PRs to main, so these surfaced on PR #28:
- cargo fmt across pool/prune/mod/ready
- ready.rs probe_exec_ready_once: single-arm match -> if let (clippy::single-match)

No functional change; release binaries unaffected.

Author: Roy Lin

src/cli/src/commands/mod.rs

@@ -34,6 +34,7 @@ pub(crate) mod network;
 mod pause;
 mod pool;
 mod port;
+mod prune;
 mod ps;
 mod pull;
 mod push;
@@ -45,7 +46,6 @@ mod run;
 mod save;
 mod seal;
 mod shell;
-mod prune;
 mod snapshot;
 mod start;
 mod stats;

src/cli/src/commands/prune.rs

@@ -60,10 +60,24 @@ mod tests {
 
     #[test]
     fn test_is_prunable_box_only_inactive() {
-        assert!(!is_prunable_box(&make_record("a", "running", "running", Some(1))));
-        assert!(!is_prunable_box(&make_record("b", "paused", "paused", Some(1))));
-        assert!(is_prunable_box(&make_record("c", "stopped", "stopped", None)));
+        assert!(!is_prunable_box(&make_record(
+            "a",
+            "running",
+            "running",
+            Some(1)
+        )));
+        assert!(!is_prunable_box(&make_record(
+            "b",
+            "paused",
+            "paused",
+            Some(1)
+        )));
+        assert!(is_prunable_box(&make_record(
+            "c", "stopped", "stopped", None
+        )));
         assert!(is_prunable_box(&make_record("d", "dead", "dead", None)));
-        assert!(is_prunable_box(&make_record("e", "created", "created", None)));
+        assert!(is_prunable_box(&make_record(
+            "e", "created", "created", None
+        )));
     }
 }

src/runtime/src/pool/warm_pool.rs

@@ -462,9 +462,10 @@ impl WarmPool {
             return Ok(t.clone());
         }
 
-        let dir = a3s_box_core::dirs_home()
-            .join("pool")
-            .join(format!("tpl-{:016x}", crate::vm::fnv1a_hash(&box_config.image)));
+        let dir = a3s_box_core::dirs_home().join("pool").join(format!(
+            "tpl-{:016x}",
+            crate::vm::fnv1a_hash(&box_config.image)
+        ));
         std::fs::create_dir_all(&dir).map_err(BoxError::IoError)?;
         let mem_file = dir.join("template.ram");
         let sock = dir.join("template.sock");
@@ -542,7 +543,10 @@ impl WarmPool {
     /// state save/restore, neither of which exist on Windows. `--snapshot-fork` is
     /// Linux/KVM-only, so this path is never reached there in practice.
     #[cfg(not(unix))]
-    async fn trigger_snapshot(_sock: &std::path::Path, _state_file: &std::path::Path) -> Result<()> {
+    async fn trigger_snapshot(
+        _sock: &std::path::Path,
+        _state_file: &std::path::Path,
+    ) -> Result<()> {
         Err(BoxError::PoolError(
             "snapshot-fork is only supported on Linux/KVM hosts".to_string(),
         ))

src/runtime/src/vm/ready.rs

@@ -22,7 +22,11 @@ impl VmManager {
         // (no cold boot), so a short grace catches an immediate restore failure while
         // saving ~200ms on the fork fast-path; a cold boot keeps the longer grace.
         #[cfg(unix)]
-        let max_wait_ms: u64 = if super::is_restore_mode(&self.config) { 40 } else { 250 };
+        let max_wait_ms: u64 = if super::is_restore_mode(&self.config) {
+            40
+        } else {
+            250
+        };
         #[cfg(not(unix))]
         let max_wait_ms: u64 = 250;
         const POLL_MS: u64 = 10;
@@ -142,13 +146,10 @@ impl VmManager {
         if let Ok(Ok(client)) =
             tokio::time::timeout(ATTEMPT_TIMEOUT, ExecClient::connect(exec_socket_path)).await
         {
-            match tokio::time::timeout(ATTEMPT_TIMEOUT, client.heartbeat()).await {
-                Ok(Ok(true)) => {
-                    tracing::debug!("restore: exec server heartbeat passed");
-                    self.exec_client = Some(client);
-                    return;
-                }
-                _ => {}
+            if let Ok(Ok(true)) = tokio::time::timeout(ATTEMPT_TIMEOUT, client.heartbeat()).await {
+                tracing::debug!("restore: exec server heartbeat passed");
+                self.exec_client = Some(client);
+                return;
             }
         }
         tracing::debug!(