feat: add multi-page support, improve template creation logic, and refine rank resolution in certificate designer

apps/backoffice/src/app/features/certificate-designer/components/BlockPropertiesPanel.tsx

@@ -135,6 +135,21 @@ export function BlockPropertiesPanel({
           />
         </Group>
 
+        <NumberInput
+          label={t('designer.blockPage', 'Page')}
+          description={t('designer.blockPageHint', 'Which sheet of the document this block prints on')}
+          value={(block.page ?? 0) + 1}
+          onChange={(value) => {
+            const index = Math.max(0, Math.min(63, Math.floor(Number(value) || 1) - 1));
+            // Omitted on the first page so a single-page design stays as it was.
+            const { page: _page, ...rest } = block;
+            onChange(index > 0 ? { ...rest, page: index } : rest);
+          }}
+          min={1}
+          max={64}
+          disabled={disabled}
+        />
+
         <Group gap="xs" grow>
           <NumberInput
             label={t('designer.blockX', 'X (%)')}