Fix template region stacking order

src/data/templates.js

@@ -6,6 +6,11 @@ const animationPresets = require('#src/web/public/js/templates/animation-presets
 const TEMPLATE_NAME_MAX_LENGTH = 255;
 const REGION_NAME_MAX_LENGTH = 255;
 
+function normalizeRegionZIndex(value) {
+  const parsed = Number(value);
+  return Number.isFinite(parsed) ? Math.max(1, Math.round(parsed)) : 1;
+}
+
 function sanitizeBackgroundColor(value) {
   const raw = String(value || '').trim();
   if (/^#[0-9a-fA-F]{6}$/.test(raw) || /^#[0-9a-fA-F]{3}$/.test(raw)) {
@@ -185,7 +190,7 @@ function extractTemplateRegions(body) {
           y: Number(region.y || 0),
           width: Number(region.width || 100),
           height: Number(region.height || 100),
-          z_index: Number(region.z_index || 0)
+          z_index: normalizeRegionZIndex(region.z_index)
         };
       }).filter((region) => region.region_key && region.label);
     }
@@ -221,7 +226,7 @@ function extractTemplateRegions(body) {
       y: Number(ys[i] || 0),
       width: Number(widths[i] || 100),
       height: Number(heights[i] || 100),
-      z_index: Number(zs[i] || 0)
+      z_index: normalizeRegionZIndex(zs[i])
     });
   }