Use build-base + linux-headers for better-sqlite3 on Alpine

g++ alone is missing musl-dev and binutils; build-base is Alpine's
equivalent of build-essential and covers the full GCC toolchain
needed by node-gyp.

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

Dockerfile

@@ -28,9 +28,9 @@ RUN apk add --no-cache dumb-init
 COPY package*.json ./
 
 # Install build tools for native modules (better-sqlite3), then install deps
-RUN apk add --no-cache python3 make g++ && \
+RUN apk add --no-cache python3 build-base linux-headers && \
     npm ci --omit=dev && \
-    apk del python3 make g++
+    apk del python3 build-base linux-headers
 
 # Copy server code
 COPY server ./server