Standardize configuration values

Always standardize configuration values to ensure consistency, reproducibility, and maintainability:

1. Pin specific versions instead of using floating tags for dependencies to ensure consistent behavior across environments. ```diff
   • image: redis:6.0
   • image: redis:6.0.20 ```
2. Centralize repeated values as environment variables or constants to avoid duplication and simplify updates. ```diff

   • curl -L https://github.com/golang-migrate/migrate/releases/download/v4.18.3/migrate.linux-amd64.tar.gz

     tar xvz

   • MIGRATE_VERSION=”v4.18.3”
   • curl -L https://github.com/golang-migrate/migrate/releases/download/$MIGRATE_VERSION/migrate.linux-amd64.tar.gz | tar xvz ```
3. Use official defaults when configuring services, then provide clear documentation for any custom values and ensure they can be overridden when needed.

   # Use environment variables with descriptive comments
   CLICKHOUSE_MAX_MEMORY_USAGE: "${CLICKHOUSE_MEM:-800000000}"  # Default ~800MB, override with CLICKHOUSE_MEM
   

This approach reduces maintenance burden, makes configuration changes safer and more deliberate, and provides better visibility into how systems are configured.