Minor ii–V–i

The minor mode reshapes the ii–V–I in three small ways. The ii becomes a half-diminished chord (m7♭5), since the natural minor's 6th degree (the ♭5 of the ii chord) is a half step lower than the major's. The V stays dominant 7, since the harmonic minor's raised 7th gives it the major 3rd it needs to function as a true V. And the i is a m7 chord instead of a maj7.

The shells overlap almost perfectly with the major-key shells: a m7♭5 has the same 3 + ♭7 as a regular m7 (the ♭5 isn't in the shell), and the V7 is identical in either mode. The difference is the resolution — both shell voices land a half step lower than they would in major (♭3 where major had 3, ♭7 where it had 7), so the cadence moves two voices at once where the major moved one. Same alternating A/B pattern everywhere else.