Implement login, add useUser hook

services/user/schema/LoginValidationSchema.ts

@@ -0,0 +1,18 @@
+import { z } from 'zod';
+
+const LoginValidationSchema = z.object({
+  username: z
+    .string({
+      required_error: 'Username is required.',
+      invalid_type_error: 'Username must be a string.',
+    })
+    .min(1, { message: 'Username is required.' }),
+  password: z
+    .string({
+      required_error: 'Password is required.',
+      invalid_type_error: 'Password must be a string.',
+    })
+    .min(1, { message: 'Password is required.' }),
+});
+
+export default LoginValidationSchema;