feat: add Zod validation schemas for all domain routes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/schemas/company-settings.schema.ts

@@ -0,0 +1,21 @@
+import { z } from 'zod';
+
+export const UpdateCompanySettingsSchema = z.object({
+  company_name: z.string().nullish(),
+  street: z.string().nullish(),
+  city: z.string().nullish(),
+  postal_code: z.string().nullish(),
+  country: z.string().nullish(),
+  company_id: z.string().nullish(),
+  vat_id: z.string().nullish(),
+  quotation_prefix: z.string().nullish(),
+  default_currency: z.string().nullish(),
+  order_type_code: z.string().nullish(),
+  invoice_type_code: z.string().nullish(),
+  default_vat_rate: z.union([z.number(), z.string()]).transform(v => Number(v)).optional(),
+  require_2fa: z.any().optional(),
+  custom_fields: z.array(z.any()).optional(),
+  supplier_field_order: z.array(z.any()).optional(),
+});
+
+export type UpdateCompanySettingsInput = z.infer<typeof UpdateCompanySettingsSchema>;