feat(pipeline): add WSKL (Wowee Skill Catalog) format

Novel open replacement for Blizzard's SkillLine.dbc +
SkillLineCategory.dbc + the AzerothCore-style player skill
base tables. The 19th open format added to the editor.

Defines every player-trackable skill: weapon proficiencies
(Swords, Axes, Bows), professions (Mining, Alchemy,
Cooking), languages (Common, Dwarvish), class
specializations (Fire, Frost, Holy, Protection), armor
proficiencies (Mail, Plate), and secondary skills (First
Aid, Lockpicking, Riding).

Cross-references with previously-added formats:
  WLCK.channel.targetId (kind=Lockpick) -> WSKL.entry.skillId
  WGOT.entry.requiredSkill              -> WSKL.entry.skillId

The starter preset's skillIds 186 (Mining) and 633
(Lockpicking) deliberately match the canonical IDs already
referenced by WGOT.makeGather and WLCK.makeDungeon —
so the demo content stack now wires together end-to-end:
WGOT herb-node requires skill 186 -> WSKL Mining at rank 1+;
WLCK bandit-strongbox channel requires skill 633 -> WSKL
Lockpicking at rank 1+.

Format:
  • magic "WSKL", version 1, little-endian
  • per skill: skillId / name / description / categoryId /
    canTrain / maxRank / rankPerLevel / iconPath

Enums:
  • CategoryId (8): Weapon / Class / Profession /
    SecondaryProfession / Language / ArmorProficiency /
    Riding / WeaponSpec

API: WoweeSkillLoader::save / load / exists / findById;
presets makeStarter (5-skill demo with cross-referenced
canonical IDs), makeProfessions (12 classic professions:
9 primary + 3 secondary), makeWeapons (16 weapon skills
with canonical SkillLine IDs and rankPerLevel=5 auto-grow).

CLI added (5 flags, 528 documented total now):
  --gen-skills / --gen-skills-professions / --gen-skills-weapons
  --info-wskl / --validate-wskl

Validator catches: skillId=0 + duplicates, empty name,
maxRank=0, unknown categoryId, suspicious maxRank=1 on
non-Language skill (only languages cap at 1), weapon skill
with rankPerLevel=0 (won't auto-grow on use).

tools/editor/cli_arg_required.cpp

@@ -52,6 +52,8 @@ const char* const kArgRequired[] = {
     "--export-wfac-json", "--import-wfac-json",
     "--gen-locks", "--gen-locks-dungeon", "--gen-locks-professions",
     "--info-wlck", "--validate-wlck",
+    "--gen-skills", "--gen-skills-professions", "--gen-skills-weapons",
+    "--info-wskl", "--validate-wskl",
     "--gen-weather-temperate", "--gen-weather-arctic",
     "--gen-weather-desert", "--gen-weather-stormy",
     "--gen-zone-atmosphere",