chore(build): pre-build Next.js to boost startup time

frontend/Dockerfile

@@ -1,40 +1,50 @@
+# ---- base stage ----
 FROM node:22-alpine AS base
 
 ENV PNPM_HOME="/pnpm"
 ENV PATH="$PNPM_HOME:$PATH"
 
 RUN corepack enable && corepack prepare pnpm@10.10.0 --activate
 
-# ---- deps stage ----
-FROM base AS deps
+# ---- build stage ----
+FROM base AS builder
+
+ENV NODE_ENV=production
+ENV NEXT_PUBLIC_LINUX_DO_CREDIT_BACKEND_URL=https://build-placeholder.invalid
+ENV LINUX_DO_CREDIT_SESSION_COOKIE_NAME=__LINUX_DO_CREDIT_SESSION_COOKIE_NAME__
+ENV LINUX_DO_CREDIT_RATE_LIMIT_ENABLED=__LINUX_DO_CREDIT_RATE_LIMIT_ENABLED__
 
 WORKDIR /app
 
 COPY package.json pnpm-lock.yaml ./
 
 RUN pnpm install --frozen-lockfile
 
-# ---- runner stage ----
-FROM base AS runner
+COPY . .
 
-WORKDIR /app
+RUN pnpm build
 
-ENV NODE_ENV=production
+RUN grep -rl \
+    -e "https://build-placeholder.invalid" \
+    -e "__LINUX_DO_CREDIT_SESSION_COOKIE_NAME__" \
+    -e "__LINUX_DO_CREDIT_RATE_LIMIT_ENABLED__" \
+    /app/.next > /app/.replace.files
 
-# accepts version argument to override package.json version
-ARG VERSION=""
+# ---- runner stage ----
+FROM base AS runner
 
-# accepts build date argument to set package.json build metadata
+ARG VERSION=""
 ARG BUILD_DATE=""
 
-COPY --from=deps /app/node_modules ./node_modules
-COPY . .
+WORKDIR /app
+
+COPY --from=builder /app .
 
-# update package.json build metadata when build args are provided
 RUN if [ -n "$VERSION" ] || [ -n "$BUILD_DATE" ]; then \
   VERSION="$VERSION" BUILD_DATE="$BUILD_DATE" node -e "const fs = require('fs'); const pkg = require('./package.json'); const version = process.env.VERSION; const buildDate = process.env.BUILD_DATE; if (version) pkg.version = version; if (buildDate) pkg.buildDate = buildDate; fs.writeFileSync('./package.json', JSON.stringify(pkg, null, 2) + '\\n')"; \
 fi
 
 EXPOSE 3000
 
-CMD ["sh", "-c", "pnpm build && pnpm start"]
+ENTRYPOINT ["./entrypoint.sh"]
+CMD ["pnpm", "start"]

frontend/entrypoint.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+
+set -e
+
+replace_placeholder() {
+  local placeholder="$1"
+  local real_value="$2"
+
+  if [ -z "$real_value" ]; then
+    echo "⚠️ WARNING: Environment variable for placeholder '${placeholder}' is not set. Skipping replacement."
+    return 0
+  fi
+
+  echo "🔍 Replacing placeholder '${placeholder}' with value '${real_value}'"
+
+  local escaped
+  escaped=$(printf '%s\n' "$real_value" | sed 's/[&/\]/\\&/g')
+
+  local files
+  if [ -f /app/.replace.files ]; then
+    files=$(grep -l "$placeholder" $(cat /app/.replace.files) 2>/dev/null || true)
+  fi
+
+  if [ -z "$files" ]; then
+    echo "⚠️  WARNING: placeholder '${placeholder}' not found in any file"
+  else
+    local count
+    count=$(echo "$files" | wc -l)
+    echo "$files" | xargs sed -i "s|${placeholder}|${escaped}|g"
+    echo "✅ Replaced '${placeholder}' in ${count} file(s)"
+  fi
+}
+
+replace_placeholder "https://build-placeholder.invalid" "$NEXT_PUBLIC_LINUX_DO_CREDIT_BACKEND_URL"
+replace_placeholder "__LINUX_DO_CREDIT_SESSION_COOKIE_NAME__" "$LINUX_DO_CREDIT_SESSION_COOKIE_NAME"
+replace_placeholder "__LINUX_DO_CREDIT_RATE_LIMIT_ENABLED__" "$LINUX_DO_CREDIT_RATE_LIMIT_ENABLED"
+
+exec "$@"

frontend/next.config.ts

@@ -5,7 +5,7 @@ const nextConfig: NextConfig = {
   experimental: {
   },
   async rewrites() {
-    const backendUrl = process.env.LINUX_DO_CREDIT_BACKEND_URL || 'http://localhost:8000';
+    const backendUrl = process.env.NEXT_PUBLIC_LINUX_DO_CREDIT_BACKEND_URL || 'http://localhost:8000';
     return [
       // 易支付兼容接口 - 创建订单
       {

frontend/proxy.ts

@@ -86,7 +86,7 @@ export function proxy(request: NextRequest) {
 
   /* API 请求：速率限制后放行 */
   if (pathname.startsWith('/api/')) {
-    const rateLimitEnabled = !!process.env.LINUX_DO_CREDIT_RATE_LIMIT_ENABLED
+    const rateLimitEnabled = process.env.LINUX_DO_CREDIT_RATE_LIMIT_ENABLED === 'true'
 
     if (rateLimitEnabled && shouldRateLimit(pathname)) {
       const identifier = sessionCookie?.value ||