feat: Add BASE_PATH support with -base image variant

Dockerfile

@@ -16,7 +16,7 @@ COPY --from=deps /app/node_modules ./node_modules
 COPY . .
 COPY docker/middleware.ts ./src
 
-ARG BASE_PATH
+ARG BASE_PATH=""
 
 ENV BASE_PATH=$BASE_PATH
 ENV NEXT_TELEMETRY_DISABLED=1
@@ -30,10 +30,12 @@ WORKDIR /app
 
 ARG PRISMA_VERSION="6.19.0"
 ARG NODE_OPTIONS
+ARG BASE_PATH=""
 
 ENV NODE_ENV=production
 ENV NEXT_TELEMETRY_DISABLED=1
 ENV NODE_OPTIONS=$NODE_OPTIONS
+ENV BASE_PATH=$BASE_PATH
 
 RUN addgroup --system --gid 1001 nodejs
 RUN adduser --system --uid 1001 nextjs