Fix Docker build: add native build tools for better-sqlite3

better-sqlite3 is a native C++ addon that requires python3, make, and g++
to compile on Alpine Linux. Added to both builder and production stages.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -2,6 +2,7 @@
 FROM node:20-alpine AS builder
 
 WORKDIR /app
+RUN apk add --no-cache python3 make g++
 COPY package*.json ./
 RUN npm ci
 
@@ -12,6 +13,7 @@ RUN npm run build
 FROM node:20-alpine
 
 WORKDIR /app
+RUN apk add --no-cache python3 make g++
 
 # Copy package files and install production deps only
 COPY package*.json ./