small fix, don't worry about it

app/backend/Dockerfile

@@ -0,0 +1,48 @@
+# Build Go API binary
+FROM golang:1.24-alpine AS go-builder
+
+RUN apk add --no-cache git ca-certificates tzdata
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main cmd/server/main.go
+
+# Build embedded Better Auth runtime dependencies
+FROM node:20-alpine AS auth-builder
+
+WORKDIR /auth
+
+COPY auth/package*.json ./
+RUN npm ci --omit=dev
+
+COPY auth/src ./src
+
+# Final runtime image (Go API + Better Auth sidecar in one container)
+FROM node:20-alpine
+
+RUN apk --no-cache add ca-certificates tzdata wget
+
+RUN addgroup -g 1001 -S appgroup && \
+    adduser -u 1001 -S appuser -G appgroup
+
+WORKDIR /app
+
+COPY --from=go-builder /app/main ./main
+COPY --from=go-builder /app/migrations ./migrations
+COPY --from=go-builder /app/migrations_goose ./migrations_goose
+COPY --from=auth-builder /auth ./auth
+
+RUN chown -R appuser:appgroup /app
+
+USER appuser
+
+EXPOSE 8080
+
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://127.0.0.1:8080/health || exit 1
+
+CMD ["./main"]