Create required tmp directories in Dockerfile

Add mkdir for tmp/pids, tmp/cache, tmp/sockets, log, db, and storage
directories to prevent Puma startup failure.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Dockerfile

@@ -11,6 +11,8 @@ RUN bundle install
 
 COPY . .
 
+RUN mkdir -p tmp/pids tmp/cache tmp/sockets log db storage
+
 RUN bundle exec rails assets:precompile 2>/dev/null || true
 
 EXPOSE 3000