PRAGMA busy_timeout=N emits its own result row, polluting the read-back parse (seed read back
'20000\nupgrade-survives' → AssertionError 'seed did not commit', failing upgrade/backup/restore ops
— though the INSERT actually committed). Switch _sqlite to 'sqlite3 -cmd ".timeout 20000"' which sets
the busy timeout silently. install+custom already green (handshake/welcome/web/tcp PASS); this fixes
the P4 lifecycle ops.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>