perf: Optimize Invariant Caching & Number Formatting in Hot Paths

Sources/ContainerPersistence/ContainerSystemConfig.swift

@@ -81,10 +81,10 @@ final public class BuildConfig: Codable, Sendable {
     public static let defaultRosetta = true
     public static let defaultCPUs = 2
     public static let defaultMemory = try! MemorySize("2048MB")
-    public static var defaultImage: String {
+    public static let defaultImage: String = {
         let tag = String(cString: get_container_builder_shim_version())
         return "ghcr.io/apple/container-builder-shim/builder:\(tag)"
-    }
+    }()
 
     public let rosetta: Bool
     public let cpus: Int
@@ -145,12 +145,12 @@ final public class DNSConfig: Codable, Sendable {
 }
 
 final public class VminitConfig: Codable, Sendable {
-    public static var defaultImage: String {
+    public static let defaultImage: String = {
         let tag = String(cString: get_swift_containerization_version())
         return tag == "latest"
             ? "vminit:latest"
             : "ghcr.io/apple/containerization/vminit:\(tag)"
-    }
+    }()
 
     public let image: String
 

Sources/ContainerPersistence/MachineConfig.swift

@@ -27,15 +27,13 @@ public struct MachineConfig: Codable, Sendable {
     public static let `default`: MachineConfig = try! .init(
         cpus: nil, memory: nil, homeMount: nil, virtualization: nil, kernelPath: nil)
 
-    public static var defaultCPUs: Int {
-        max(ProcessInfo.processInfo.processorCount / 2, 4)
-    }
+    public static let defaultCPUs: Int = max(ProcessInfo.processInfo.processorCount / 2, 4)
 
-    public static var defaultMemory: MemorySize {
+    public static let defaultMemory: MemorySize = {
         let bytes = max(ProcessInfo.processInfo.physicalMemory / 2, 1024 * 1024 * 1024)
         let gb = bytes / (1024 * 1024 * 1024)
         return try! MemorySize("\(gb)gb")
-    }
+    }()
 
     public static let defaultHomeMount: HomeMountOption = .rw
 

Sources/TerminalProgress/Int+Formatted.swift

@@ -42,11 +42,6 @@ extension Int {
     }
 
     func formattedNumber() -> String {
-        let formatter = NumberFormatter()
-        formatter.numberStyle = .decimal
-        guard let formattedNumber = formatter.string(from: NSNumber(value: self)) else {
-            return ""
-        }
-        return formattedNumber
+        self.formatted(.number)
     }
 }