fix: fix PWA for mobile

frontend/Dockerfile

@@ -1,10 +1,18 @@
-FROM node:22-alpine AS builder
+FROM node:22 AS builder
+
+RUN apt-get update && apt-get install -y --no-install-recommends librsvg2-bin && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app
 COPY package.json package-lock.json* ./
 RUN npm ci
 
 COPY . .
+
+# Generate PNG icons from SVG source
+RUN mkdir -p public/icons && \
+    rsvg-convert -w 192 -h 192 public/icon-source.svg -o public/icons/icon-192.png && \
+    rsvg-convert -w 512 -h 512 public/icon-source.svg -o public/icons/icon-512.png
+
 RUN npm run build
 
 FROM nginx:alpine