chore: import upstream snapshot with attribution

Sources/ContainerResource/Volume/VolumeResource.swift

@@ -0,0 +1,90 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2026 Apple Inc. and the container project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+import Foundation
+
+/// A volume resource, representing a configured volume.
+public struct VolumeResource: ManagedResource {
+    /// The volume's configuration — its persistent, intrinsic properties.
+    public let configuration: VolumeConfiguration
+
+    // MARK: ManagedResource
+
+    /// The unique identifier for this volume. Identical to ``VolumeConfiguration/name``.
+    public var id: String { configuration.name }
+
+    /// The user-assigned name for this volume. For volumes, name and ID are the same.
+    public var name: String { configuration.name }
+
+    /// The time at which this volume was created.
+    public var creationDate: Date { configuration.creationDate }
+
+    /// Key-value labels for this volume. If the underlying
+    /// ``VolumeConfiguration/labels`` dictionary contains values that fail
+    /// ``ResourceLabels`` validation, this returns an empty label set.
+    public var labels: ResourceLabels {
+        (try? ResourceLabels(configuration.labels)) ?? ResourceLabels()
+    }
+
+    /// Whether this is an anonymous volume (detected via the configuration's labels).
+    public var isAnonymous: Bool { configuration.isAnonymous }
+
+    // MARK: Initialization
+
+    /// Creates a volume resource.
+    ///
+    /// - Parameters:
+    ///   - configuration: The volume's intrinsic configuration.
+    public init(configuration: VolumeConfiguration) {
+        self.configuration = configuration
+    }
+}
+
+extension VolumeResource {
+    public static let volumeNamePattern = "^[A-Za-z0-9][A-Za-z0-9_.-]*$"
+
+    /// Returns `true` if `name` is a syntactically valid volume identifier.
+    public static func nameValid(_ name: String) -> Bool {
+        guard name.count <= 255 else { return false }
+
+        do {
+            let regex = try Regex(volumeNamePattern)
+            return (try? regex.wholeMatch(in: name)) != nil
+        } catch {
+            return false
+        }
+    }
+}
+
+// MARK: - Codable
+
+extension VolumeResource {
+    enum CodingKeys: String, CodingKey {
+        case id
+        case configuration
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encode(id, forKey: .id)
+        try container.encode(configuration, forKey: .configuration)
+    }
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        self.configuration = try container.decode(VolumeConfiguration.self, forKey: .configuration)
+    }
+}