refactor: change null to undefined

src/lib/services/imageService.ts

@@ -87,7 +87,7 @@ export class ImageService {
       }
 
       // Find image item
-      let imageItem: DataTransferItem | null = null;
+      let imageItem: DataTransferItem | undefined = undefined;
       for (let i = 0; i < items.length; i++) {
         if (items[i].type.indexOf("image") !== -1) {
           imageItem = items[i];
@@ -184,6 +184,7 @@ export class ImageService {
   private fileToBase64(file: File): Promise<string> {
     return new Promise((resolve, reject) => {
       const reader = new FileReader();
+      // TODO: look for a better way to handle errors non strings
       reader.onload = () => resolve(reader.result as string);
       reader.onerror = () => reject(new ImageError("Ошибка чтения файла"));
       reader.readAsDataURL(file);

src/lib/types/panel.ts

@@ -42,7 +42,7 @@ export interface ImageCropResult {
 
 export interface UIState {
   isLoading: boolean;
-  error: string | null;
+  error: string | undefined;
   currentStep: "upload" | "crop" | "text" | "preview";
   showCropModal: boolean;
   showTextManager: boolean;

src/lib/utils/panelStorage.ts

@@ -1,4 +1,3 @@
-
 import type { Panel } from "../types/panel";
 import { ImageError } from "../types/errors";
 import { handleError, logError } from "./errorHandler";
@@ -72,13 +71,13 @@ export class PanelStorage {
   /**
    * Загружает панель по ID
    */
-  getPanelById(id: string): Panel | null {
+  getPanelById(id: string): Panel | undefined {
     try {
       const panels = this.getAllPanels();
-      return panels.find((p) => p.id === id) || null;
+      return panels.find((p) => p.id === id) || undefined;
     } catch (error) {
       logError(error, "Failed to get panel by id");
-      return null;
+      return undefined;
     }
   }