Generate asset versions during Docker builds

Dockerfile

@@ -10,6 +10,8 @@ COPY public ./public
 COPY server ./server
 COPY shared ./shared
 COPY db/migrations ./db/migrations
+COPY scripts ./scripts
+RUN node scripts/stamp-asset-version.mjs
 
 # The optional Pi agent configuration is mounted read-only here at runtime.
 ENV HOME=/home/node