XCOTA TAG V5.1 — two-player Gambit edition

V5.1 fixes the Windows drag/drop input binding and ZIP layout handling.
The generated 13-fighter game is byte-for-byte the released V5 game.
Gambit replaces Akuma; Juggernaut and Magneto remain selectable.

BUILD ON WINDOWS

1. Extract xcota-tag-v5.1-two-player.zip into its own writable folder.
2. Select BOTH clean game ZIPs: X-Men: Children of the Atom Euro 950331
   (normally xmcota.zip) and Marvel vs. Capcom Euro 980123 (normally mvsc.zip).
3. Drag both selected files together onto BUILD XCOTA V5.1.cmd.
   Either order works; paths with spaces are supported.
4. The finished game is output/xmcota.zip. Your originals are unchanged.

The builder also accepts one outer ZIP containing those two game ZIPs.
Keep the game ZIPs intact inside it. Do not mix loose members from different
games into one ZIP. A game ZIP may have its members flat or under one common
folder. Missing, modified, duplicate or unsupported members are refused.

If no files were passed, the error now lists the required games and received
inputs. Extract the builder first; don't run it inside a ZIP preview.
If a different output already exists, use a fresh builder folder.

XCOTA is the product shorthand, not a required source filename. The normal
game archive is xmcota.zip and its required original key is xmcota.key INSIDE
that archive. Keeping a loose key next to an incomplete ZIP is insufficient.
Identity is checked from the members, not the archive's name.
V4.1 also accepted xmcotau, xmcotaj and xmcotar1d source revisions. V5's
Gambit recipe requires the Euro 950331 parent; those older source revisions
are not interchangeable with it. V5.1 retains this requirement.

Only Windows inbox PowerShell 5.1 and .NET are required. No Python, SDK or
downloaded ROM/key is used. BUILD XCOTA V5.cmd remains a compatibility alias.

PLAY

Use the generated xmcota.zip in your existing two-player XCOTA setup. Retain
the output name. Online players must use identical generated members.

MAME: run from its command line with the generated output folder FIRST in
the ROM search path. MAME also needs the clean qsound_hle.zip BIOS containing
dl-1425.bin (24576 bytes). Add your existing BIOS folder to that search path.
Patched-ROM checksum warnings are expected; a missing required BIOS is a
different fatal error. The ROM menu's original-set audit can reject a mod.

Pick two fighters per side. MP+HK tags; LK+MP in hitstun spends one bar to
break. QCF+MP+HK calls supported team supers; QCB+MP+HK starts timed Duo.
Both team actions require full meter and a living partner. Boss teams use
Duo; their team supers stay disabled. Storm and Iceman retain their commands.

Special is a SEPARATE four-source, 17-fighter, four-controller RetroArch
edition. Use its own builder and matching core, not a renamed two-player ZIP.

V5.1 changes installers and instructions. The V5 game/core evidence carries
forward; new converter checks are recorded in the V5.1 release receipts.
