fix: all item/sub-object schemas accept string numbers from form inputs

Fixed offers, orders, attendance, scope-templates schemas — quantity,
unit_price, position, hours, minutes now use z.union([z.number(), z.string()])
with transform instead of bare z.number().

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

src/schemas/scope-templates.schema.ts

@@ -4,7 +4,7 @@ const ScopeSectionSchema = z.object({
   title: z.string().nullish(),
   title_cz: z.string().nullish(),
   content: z.string().nullish(),
-  position: z.number().optional(),
+  position: z.union([z.number(), z.string()]).transform(v => Number(v)).optional(),
 });
 
 export const CreateScopeTemplateSchema = z.object({