feat(http): add getApiErrorMessage for unified API error copy

Made-with: Cursor

app/utils/http/error-message.ts

@@ -0,0 +1,42 @@
+export function getApiErrorMessage(error: unknown): string {
+  if (error && typeof error === 'object') {
+    const e = error as Record<string, unknown>
+    const data = e.data
+    if (data && typeof data === 'object' && data !== null) {
+      const m = (data as Record<string, unknown>).message
+      if (typeof m === 'string' && m.trim().length > 0) {
+        return m
+      }
+    }
+    const sm = e.statusMessage
+    if (typeof sm === 'string' && sm.trim().length > 0) {
+      return sm
+    }
+  }
+
+  if (error instanceof Error && error.message.trim().length > 0) {
+    return error.message
+  }
+
+  if (error && typeof error === 'object' && 'statusCode' in error) {
+    const code = (error as { statusCode?: number }).statusCode
+    if (code === 401) {
+      return '登录已失效，请重新登录'
+    }
+    if (code === 403) {
+      return '没有权限执行此操作'
+    }
+    if (code === 404) {
+      return '请求的资源不存在'
+    }
+    if (typeof code === 'number' && code >= 500) {
+      return '服务暂时不可用，请稍后重试'
+    }
+  }
+
+  if (error instanceof TypeError) {
+    return '网络异常，请检查连接后重试'
+  }
+
+  return '请求失败，请稍后重试'
+}