import Foundation public enum Sub2APISettingsError: LocalizedError, Equatable, Sendable {    case invalidBaseURL     public var errorDescription: String? {        "sub2api base URL must use HTTPS, or loopback HTTP for local development, without embedded credentials."    }} public enum Sub2APISettingsReader {    public static let apiKeyEnvironmentKey = "SUB2API_API_KEY"    public static let baseURLEnvironmentKey = "SUB2API_BASE_URL"     public static func apiKey(        environment: [String: String] = ProcessInfo.processInfo.environment) -> String?    {        self.cleaned(environment[self.apiKeyEnvironmentKey])    }     public static func baseURL(        environment: [String: String] = ProcessInfo.processInfo.environment) -> URL?    {        guard let raw = self.cleaned(environment[self.baseURLEnvironmentKey]) else { return nil }        let validator = ProviderEndpointOverrideValidator()        guard let url = validator.validatedURLAllowingLoopbackHTTP(raw),              url.query == nil,              url.fragment == nil        else { return nil }        return url    }     public static func validateBaseURL(        environment: [String: String] = ProcessInfo.processInfo.environment) throws    {        guard self.baseURL(environment: environment) != nil else {            throw Sub2APISettingsError.invalidBaseURL        }    }     static func cleaned(_ raw: String?) -> String? {        guard var value = raw?.trimmingCharacters(in: .whitespacesAndNewlines), !value.isEmpty else {            return nil        }        if (value.hasPrefix("\"") && value.hasSuffix("\"")) ||            (value.hasPrefix("'") && value.hasSuffix("'"))        {            value = String(value.dropFirst().dropLast())        }        value = value.trimmingCharacters(in: .whitespacesAndNewlines)        return value.isEmpty ? nil : value    }}