Continues the ConfigLoader.cpp domain split. parseRotationString and
parsePlacedModules are only used by loadShips, so they move along as
domain-local anonymous-namespace helpers rather than into TomlHelpers.
Pure move; no logic change.
Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YHcUerKAZKWNvSKJxYKbnG
