rollback(docker): restore Alpine base for stability, DWG→DXF disabled

Dockerfile

@@ -1,12 +1,10 @@
 
-# Stage 1: Dependencies (Ubuntu base)
-FROM node:20-bookworm AS deps
+FROM node:20-alpine AS deps
 WORKDIR /app
 COPY package.json package-lock.json ./
 RUN npm ci
 
-# Stage 2: Build
-FROM node:20-bookworm AS builder
+FROM node:20-alpine AS builder
 WORKDIR /app
 COPY --from=deps /app/node_modules ./node_modules
 COPY . .
@@ -24,23 +22,14 @@ RUN npx prisma generate
 
 RUN npm run build
 
-# Stage 3: Runner (Ubuntu base)
-FROM node:20-bookworm AS runner
+FROM node:20-alpine AS runner
 WORKDIR /app
 
 ENV NODE_ENV=production
 
-# Install dependencies for all features
-# - gdal/ogr2ogr for GeoPackage export
-# - ghostscript+qpdf for extreme PDF compression
-# - libredwg for DWG→DXF conversion
-RUN apt-get update && \
-		apt-get install -y --no-install-recommends \
-			gdal-bin ghostscript qpdf build-essential git ca-certificates libredwg-tools && \
-		rm -rf /var/lib/apt/lists/*
+RUN apk add --no-cache gdal gdal-tools ghostscript qpdf
 
-# Note: DWG→DXF conversion now enabled via libredwg (dwg2dxf)
-# If libredwg-tools is missing, manual build from source may be required
+# Note: DWG→DXF conversion not available in Alpine (libredwg missing)
 
 RUN addgroup --system --gid 1001 nodejs
 RUN adduser --system --uid 1001 nextjs