1d880fdc5ff25f8e2f53d8351db97f1a4bb30da7
Replaces parallel random-access unitig iteration with a sequential mmap-based iterator for MPHF construction, eliminating the build-time `.idx` dependency by deferring index generation until after persistence. Updates `CLAUDE.md` to treat existing code as a hypothesis, mandating proactive removal of obsolete legacy constructs rather than preserving them out of inertia.