Simplify admin user creation in entrypoint

Dockerfile

@@ -17,14 +17,6 @@ WORKDIR /app
 # Install dependencies
 RUN apk add --no-cache mariadb mariadb-client mariadb-server-utils nginx bash
 
-# Initialize MariaDB directories and schema
-RUN mkdir -p /run/mysqld /var/lib/mysql && \
-    chown -R mysql:mysql /run/mysqld /var/lib/mysql && \
-    mysql_install_db --user=mysql --basedir=/usr --datadir=/var/lib/mysql
-
-# Copy built frontend to nginx
-COPY --from=builder /build/dist /usr/share/nginx/html
-
 # Copy server files
 COPY server/package*.json ./server/
 RUN cd ./server && npm ci