The post-coverage restore step ran `make clean` (which also wipes
Test/GTest, Test/Integration and Test/Components/*) but only rebuilt
`core apps`, leaving MainGTest.ex/IntegrationTests.ex deleted after
every --cpp-coverage run instead of restored to their plain (non-gcov)
form.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>