check_source_paths read the trees profiles pin from source and upstream
only, so the two platform trees the record now holds for pin_build
files read as orphaned and the record as stale.
install.py tells a MiSTer card by its MiSTer binary and menu.rbf since
73b82375d. installer.md said so, the FAQ and the README did not, and sent a
MiSTer user to --dest the card's root, where nothing reads the files.
The site test modules were cut by review pass (test_site_r2_css to test_site_r5_wiki): the passes of one subject become one module, and the modules that stood alone take the name of what they hold. The installer test classes named after a review take the name of what they test. One test left --manifest set for the tests after it, which the new order showed: it now resets the sources.