[Question] Vertex Pt.1/75 solder variant matrix pins (cc @JackyJia73)

Hi @JackyJia73 -

I'm working on a PR to add the solder variant of the Vertex Pt.1/75 to qmk_firmware as a sibling to the existing vertex/t75 (hotswap).

What I have:

• VID: 0x28E9
• PID: 0x3003 (vs hotswap 0x3006)
• Matrix: 6 rows × 16 cols (vs hotswap 6×15)
• Supports ISO Enter, split backspace, split right shift, and WK/Tsangan bottom row

The existing hotswap keyboard.json uses these matrix pins:

• cols: B0, B2, B10, B11, A15, B3, B4, B5, B6, B7, B8, B9, B12, B13, B14
• rows: A0, A7, A6, A5, A4, A3

I'm assuming columns 0-14 and all rows are wired identically on the solder PCB. Could you confirm:

1. The GPIO pin for the 16th column (col 15) on the solder variant?
2. Whether columns 0-14 and rows match the hotswap as I've assumed?

I'd be happy to submit the PR myself once I have the pin info, or if you'd prefer to handle it yourself I'll close this. Either works.

Thanks!