✨ api: Add timeout error handling and simplify theme payloads

Author: shp7724

SNUTT/Modules/Feature/APIClientInterface/Sources/Error/APIClientError.swift

@@ -5,6 +5,7 @@
 //  Copyright © 2025 wafflestudio.com. All rights reserved.
 //
 
+import Foundation
 import OpenAPIRuntime
 
 public enum APIClientError: Error {
@@ -53,4 +54,14 @@ extension Error {
             false
         }
     }
+
+    public var isTimeoutError: Bool {
+        switch self {
+        case let error as ClientError:
+            let nsError = error.underlyingError as NSError
+            return nsError.domain == NSURLErrorDomain && nsError.code == NSURLErrorTimedOut
+        default:
+            return false
+        }
+    }
 }

SNUTT/Modules/Feature/Themes/Sources/Infra/ThemeAPIRepository.swift

@@ -40,18 +40,16 @@ public struct ThemeAPIRepository: ThemeRepository {
 }
 
 extension Theme {
+    private var colorPayloads: [Components.Schemas.ColorSet] {
+        colors.map { .init(bg: $0.bgHex, fg: $0.fgHex) }
+    }
+
     fileprivate func toAddPayload() -> Components.Schemas.TimetableThemeAddRequestDto {
-        .init(
-            colors: colors.map { .init(bg: $0.bgHex, fg: $0.fgHex) },
-            name: name
-        )
+        .init(colors: colorPayloads, name: name)
     }
 
     fileprivate func toModifyPayload() -> Components.Schemas.TimetableThemeModifyRequestDto {
-        .init(
-            colors: colors.map { .init(bg: $0.bgHex, fg: $0.fgHex) },
-            name: name
-        )
+        .init(colors: colorPayloads, name: name)
     }
 }