feat(editor): add WGRP (Group Composition) open catalog format

Novel replacement for the hardcoded LFG / Dungeon Finder
group-composition rules. Defines per-instance role
quotas (tanks / healers / dps), party-size bounds, and
spec-gating. Cross-references WMS for mapId, WCDF for
difficulty.

Three preset emitters covering the canonical raid sizes:
makeFiveMan (Classic 1T/1H/3D, Heavy-Heal trash 1T/2H/2D,
Roleless 5D speedrun), makeRaid10 (Standard 2T/3H/5D,
HealingHeavy 2T/4H/4D, MeleeStack 1T/2H/7D for cleave
fights), makeRaid25 (Standard 2T/6H/17D, HealingHeavy
1T/8H/16D, ZergDPS 0T/4H/21D for tank-immune fights).

Validator rejects role-sums that exceed maxPartySize
(unfulfillable comp), enforces min<=max, no duplicate
ids; warns on non-standard sizes (5/10/25/40 only) and
zero-tank comps so authors confirm intent. Caught one
real bug during smoke-test where a 25-player Wintergrasp
preset was mis-bound to a 10-man maxPartySize.

Format count 95 -> 96. CLI flag count 1090 -> 1095.

tools/editor/cli_format_table.cpp

@@ -98,6 +98,7 @@ constexpr FormatMagicEntry kFormats[] = {
     {{'W','S','T','C'}, ".wstc",  "pets",      "--info-wstc",      "Hunter stable slot catalog"},
     {{'W','S','T','M'}, ".wstm",  "stats",     "--info-wstm",      "Stat modifier curve catalog"},
     {{'W','A','C','T'}, ".wact",  "ui",        "--info-wact",      "Action bar layout catalog"},
+    {{'W','G','R','P'}, ".wgrp",  "social",    "--info-wgrp",      "Group composition catalog"},
     {{'W','F','A','C'}, ".wfac",  "factions",  nullptr,            "Faction catalog"},
     {{'W','L','C','K'}, ".wlck",  "locks",     nullptr,            "Lock catalog"},
     {{'W','S','K','L'}, ".wskl",  "skills",    nullptr,            "Skill catalog"},