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/cli/args.rs

@@ -85,24 +85,24 @@ pub struct Cli {
     /// Include removable devices (e.g., USB sticks) during discovery (default: false)
     #[arg(long = "allow-removable", default_value_t = false)]
     pub allow_removable: bool,
- 
+
     /// Attempt to mount existing filesystems based on on-disk headers; no partitioning or mkfs.
     /// Non-destructive mounting flow; uses UUID= sources and policy from config.
     #[arg(long = "mount-existing", default_value_t = false)]
     pub mount_existing: bool,
- 
+
     /// Report current initialized filesystems and mounts without performing changes.
     #[arg(long = "report-current", default_value_t = false)]
     pub report_current: bool,
- 
+
     /// Print detection and planning summary as JSON to stdout (non-default)
     #[arg(long = "show", default_value_t = false)]
     pub show: bool,
- 
+
     /// Write detection/planning JSON report to the given path
     #[arg(long = "report")]
     pub report: Option<String>,
- 
+
     /// Execute destructive actions (apply mode). When false, runs preview-only.
     #[arg(long = "apply", default_value_t = false)]
     pub apply: bool,
@@ -111,4 +111,4 @@ pub struct Cli {
 /// Parse CLI arguments (non-interactive; suitable for initramfs).
 pub fn from_args() -> Cli {
     Cli::parse()
-}
+}