feat(editor): add WSPV (Spell Variant) — 113th open format

Novel replacement for the implicit context-conditional
spell substitution rules vanilla WoW encoded across
SpellSpecificType, SpellEffect.EffectMechanic override
fields, and the proc-modified spell tables in
SpellProcEvent. Each entry binds one base spell to a
variant spell that activates when a runtime condition
is met (player in a specific stance, talent talented,
racial buff active, weapon equipped, aura present).

Six conditionKind values cover the full substitution
surface: Stance / Form / Talent / Race / EquippedWeapon
/ AuraActive. The conditionValue field is polymorphic —
its semantics depend on conditionKind (a stance spellId,
a talentId, a race bit, etc.). The spell-cast pipeline
iterates findByBaseSpell at cast time and picks the
highest-priority variant whose condition is satisfied,
falling through to the base spell if none matches.

Three preset emitters demonstrating the pattern:
makeWarriorStance (4 stance-conditional Warrior
variants — Heroic Strike Berserker damage bonus,
Battle baseline, Mocking Blow Defensive AoE taunt,
Pummel Berserker-only gate), makeTalentMod (4 talent-
modified variants — Frostbolt + Brain Freeze instant,
Lava Burst + Flame Shock auto-crit, Earth Shield +
Improved bonus heal, Ferocious Bite + Berserk),
makeRacial (4 race-gated racials — Stoneform Dwarf,
War Stomp Tauren, Berserking Troll, Will of the
Forsaken).

Validator's most novel check is the (baseSpell,
conditionKind, conditionValue, priority) 4-tuple
uniqueness — two variants with all four matching
would tie at runtime and resolve non-deterministically
(the spell-cast pipeline's std::sort by priority is
stable but the underlying iteration order is undefined
when priorities tie). Packs the tuple into 64 bits
(base 32 | value 16 | kind 8 | prio 8) for set lookup.

Format count 112 -> 113. CLI flag count 1213 -> 1218.

tools/editor/cli_format_table.cpp

@@ -115,6 +115,7 @@ constexpr FormatMagicEntry kFormats[] = {
     {{'W','M','N','L'}, ".wmnl",  "worldmap",  "--info-wmnl",      "Minimap multi-level catalog"},
     {{'W','P','C','R'}, ".wpcr",  "pets",      "--info-wpcr",      "Pet care + action catalog"},
     {{'W','M','V','C'}, ".wmvc",  "cinematic", "--info-wmvc",      "Movie credits roll catalog"},
+    {{'W','S','P','V'}, ".wspv",  "spells",    "--info-wspv",      "Spell variant 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"},