feat: update Dockerfile and docker-compose to work with new svelte frontend

Dockerfile

@@ -1,51 +1,34 @@
-# Build stage for Elm frontend
-FROM node:25-alpine AS elm-build
+FROM node:22-alpine AS frontend-builder
 
-WORKDIR /frontend
+WORKDIR /src/frontend
 
-# Install Elm
-RUN npm install -g elm@latest-0.19.1
+COPY frontend/package.json frontend/package-lock.json ./
+RUN npm ci
 
-# Copy Elm files
-COPY frontend/elm.json .
-COPY frontend/src ./src
+COPY frontend/ ./
+RUN npm run build
 
-# Build Elm app
-RUN elm make src/Main.elm --optimize --output=elm.js
+FROM golang:1.25.5-alpine AS backend-builder
 
-# Build stage for Go backend
-FROM golang:1.25.3-alpine AS go-build
+WORKDIR /src/backend
 
-WORKDIR /app
-
-# Copy go mod files
 COPY backend/go.mod backend/go.sum ./
 RUN go mod download
 
-# Copy backend source
 COPY backend/ ./
 
-# Build Go binary
-RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main .
+COPY --from=frontend-builder /src/frontend/dist ./dist
+
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o timetracker .
 
-# Final stage
 FROM alpine:latest
 
 RUN apk --no-cache add ca-certificates tzdata
 
-WORKDIR /root/
+WORKDIR /app
 
-# Copy Go binary from build stage
-COPY --from=go-build /app/main .
+COPY --from=backend-builder /src/backend/timetracker .
 
-# Create static directory
-RUN mkdir -p /root/static
-
-# Copy Elm build artifacts
-COPY --from=elm-build /frontend/elm.js /root/static/
-COPY frontend/public/index.html /root/static/
-
-# Create volume for database
 VOLUME ["/data"]
 
 ENV PORT=8080
@@ -53,4 +36,4 @@ ENV DB_PATH=/data/timetracking.db
 
 EXPOSE 8080
 
-CMD ["./main"]
+CMD ["./timetracker"]

docker-compose.yml

@@ -2,23 +2,18 @@ services:
   timetracking:
     build: .
     container_name: school-timetracking
+    restart: unless-stopped
     ports:
       - "8080:8080"
     environment:
       - PORT=8080
+      - ENVIRONMENT=production
       - DB_PATH=/data/timetracking.db
-      - JWT_SECRET=your-default-secret-change-me
-      - TZ=Europe/Berlin # Optional: Zeitzone
+      - JWT_SECRET=change-me-to-something-secure-and-long
+      - TZ=Europe/Berlin
+      - CORS_ALLOWED_ORIGINS=http://localhost:8080
     volumes:
-      - timetracking-data:/data
-    restart: unless-stopped
-    networks:
-      - timetracking-net
+      - timetracking_data:/data
 
 volumes:
-  timetracking-data:
-    driver: local
-
-networks:
-  timetracking-net:
-    driver: bridge
+  timetracking_data: