Fix missing framework-search-path response file on project regeneration

Fixes a bug where regenerating a project over an existing Derived/ directory could delete the consolidated framework-search-path response file, causing builds to fail with errors such as “no such file or directory: ‘@…/Derived/FrameworkSearchPaths/.resp’”. The framework search path setup is now written as a graph mapper side effect, so it is generated after the Derived/ cleanup and survives regeneration. This restores buildability for large projects, especially those with many binary-cached dependencies on CI.