feat: add standalone Dockerfile with frontend and backend

Dockerfile.standalone

@@ -0,0 +1,39 @@
+# Build frontend
+FROM node:22-alpine AS frontend-builder
+WORKDIR /app/web
+COPY web/package.json web/pnpm-lock.yaml ./
+RUN npm install -g pnpm && pnpm install --frozen-lockfile
+COPY web/ .
+RUN pnpm build
+
+# Build backend
+FROM golang:1.24-alpine AS backend-builder
+WORKDIR /app
+RUN apk add --no-cache git
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o /taskpool .
+
+# Production stage
+FROM alpine:3.19
+RUN apk add --no-cache nginx supervisor
+
+# Copy frontend
+COPY --from=frontend-builder /app/web/dist /usr/share/nginx/html
+
+# Copy backend
+COPY --from=backend-builder /taskpool /app/taskpool
+
+# Copy nginx config (modified for localhost)
+COPY nginx-standalone.conf /etc/nginx/http.d/default.conf
+
+# Copy supervisor config
+COPY supervisord.conf /etc/supervisord.conf
+
+# Create data directories
+RUN mkdir -p /app/data /app/configs /app/envs /app/logs
+
+EXPOSE 3000 8052
+
+CMD ["/usr/bin/supervisord", "-c", "/etc/supervisord.conf"]