fix: make ApiError generic to preserve type information

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/utils/http/factory.ts

@@ -8,8 +8,8 @@ export type ApiResponse<T = unknown> = {
 }
 
 /** Wraps API error responses, preserving the data field for field-level error handling */
-export class ApiError extends Error {
+export class ApiError<T = unknown> extends Error {
-    constructor(message: string, public data: unknown) {
+    constructor(message: string, public data: T) {
         super(message)
         this.name = 'ApiError'
     }