On native Windows the text-mode ``handle.write("\n")`` that seeds an empty
``--lock-file`` is translated to ``\r\n``, so a fresh lock file is two bytes
and the msvcrt regression test fails on the platform it protects. Seed the
file with ``os.write(fd, b"\0")`` on the descriptor instead: exactly one byte
whatever the text-mode newline translation. The Windows-branch tests now run
under a ``\n`` -> ``\r\n`` translating ``open`` so this failure reproduces
on any host.
Remove the two ``... not in src`` assertions added for the previous review
from test_issue2628: the behaviours they hinted at (every missing-index
projection uses the pre-aggregated ordering; listing never creates an
index) are already asserted through query plans, result equivalence and
``PRAGMA index_list`` in test_pr7445_readonly_review_followups.py,
test_state_db_readonly_readers.py and test_issue3887_index_prime.py.