feat(api): upgrade zod to v4 and implement api docs and client generation

src/lib/auth/validation.ts

@@ -0,0 +1,53 @@
+import zod from 'zod/v4';
+import {
+  emailSchema,
+  firstNameSchema,
+  lastNameSchema,
+  newUserEmailServerSchema,
+  newUserNameServerSchema,
+  passwordSchema,
+  userNameSchema,
+} from '@/app/api/user/validation';
+
+// ----------------------------------------
+//
+// Login Validation
+//
+// ----------------------------------------
+export const loginSchema = zod.object({
+  email: emailSchema.or(userNameSchema),
+  password: zod.string().min(1, 'Password is required'),
+});
+
+// ----------------------------------------
+//
+// Register Validation
+//
+// ----------------------------------------
+export const registerServerSchema = zod
+  .object({
+    firstName: firstNameSchema,
+    lastName: lastNameSchema,
+    email: newUserEmailServerSchema,
+    password: passwordSchema,
+    confirmPassword: passwordSchema,
+    username: newUserNameServerSchema,
+  })
+  .refine((data) => data.password === data.confirmPassword, {
+    message: 'Passwords do not match',
+    path: ['confirmPassword'],
+  });
+
+export const registerSchema = zod
+  .object({
+    firstName: firstNameSchema,
+    lastName: lastNameSchema,
+    email: emailSchema,
+    password: passwordSchema,
+    confirmPassword: passwordSchema,
+    username: userNameSchema,
+  })
+  .refine((data) => data.password === data.confirmPassword, {
+    message: 'Passwords do not match',
+    path: ['confirmPassword'],
+  });