mount: prefer boot disk ESP and run cargo fmt

* choose ESP matching the primary data disk when multiple ESPs exist,
  falling back gracefully for single-disk layouts
* keep new helper to normalize device names and reuse the idempotent
  mount logic
* apply cargo fmt across the tree

src/types.rs

@@ -15,15 +15,15 @@
 // - Keep field names and enums stable; update docs/SCHEMA.md when public surface changes.
 // REGION: RESPONSIBILITIES-END
 
-use serde::{Deserialize, Serialize};
 use clap::ValueEnum;
+use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct LoggingConfig {
     /// Log level: "error" | "warn" | "info" | "debug"
-    pub level: String,     // default "info"
+    pub level: String, // default "info"
     /// When true, also log to /run/zosstorage/zosstorage.log
-    pub to_file: bool,     // default false
+    pub to_file: bool, // default false
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -55,7 +55,11 @@ pub enum Topology {
     #[value(alias = "ssd-hdd-bcachefs")]
     SsdHddBcachefs,
     /// Multi-device bcachefs with two replicas (data+metadata).
-    #[value(alias = "bcachefs2-copy", alias = "bcachefs-2copy", alias = "bcachefs-2-copy")]
+    #[value(
+        alias = "bcachefs2-copy",
+        alias = "bcachefs-2copy",
+        alias = "bcachefs-2-copy"
+    )]
     Bcachefs2Copy,
     /// Optional mirrored btrfs across two disks when explicitly requested.
     #[value(alias = "btrfs-raid1")]
@@ -205,4 +209,4 @@ pub struct Config {
     pub mount: MountScheme,
     /// Report output configuration.
     pub report: ReportOptions,
-}
+}