merge: combine all features from both codebases - mobile dashboard + layer panel + notifications + shares + all fixes

frontend/src/services/exportService.ts

@@ -156,7 +156,7 @@ function elementToSVG(el: CADElement, layerColor?: string): string | null {
   const stroke = (p.stroke as string) || layerColor || '#000000';
   const sw = p.strokeWidth ?? 1;
   const fill = p.fill as string || 'none';
-  const style = `stroke="${stroke}" stroke-width="${sw}" fill="${fill}"`;
+  const style = `stroke="${stroke}" strokeWidth="${sw}" fill="${fill}"`;
 
   switch (el.type) {
     case 'line': {