v33 milestone: first M->S application data crossing on silicon (2026-06-10).

Bitstream built from e2fefd4 + the deskew pipeline (c5f24b6) and run
with the M12 bootstrap (7702f07); this tag points at the first commit
whose tree matches what was on the boards.

Result: bilateral 16/16 cal+lock, FCSM=4 bilateral, 4-pkt AHB_TX burst
landed byte-perfect in the slave RX FIFO (hdr=0x00240000 p0=0xDA7A0000).
Master tap16 / slave tap7. Known residual: S->M credit decode
intermittent (~97%, marginal eye) — superseded by the new PHY.