feat(editor): add WSCS (Skill Cost) open catalog format

Open replacement for Blizzard's SkillCostsData.dbc plus the
per-rank training cost tables. Defines the tiered progression of
trainable skills: each rank unlocks a skill range, requires a
minimum character level, and costs a fixed amount of gold to
learn.

The canonical 6-tier profession progression captured by the
default preset:
  Apprentice    skill 0-75     lvl 5    1s
  Journeyman    skill 50-150   lvl 10   5s
  Expert        skill 125-225  lvl 20   1g
  Artisan       skill 200-300  lvl 35   5g
  Master        skill 275-375  lvl 50   10g
  Grand Master  skill 350-450  lvl 65   25g

Same shape applies to weapon skills (free, level-gated, capped at
5x char level) and riding skills (canonical Vanilla / TBC / WotLK
gold costs from 90g Apprentice through 5000g Artisan flying down
to 1000g Cold Weather Flying).

Five costKind values cover the full training-skill space
(Profession / WeaponSkill / RidingSkill / ClassSkill / Misc).
Each entry's copperCost stores the cost in copper (1g = 10000c)
which the info renderer pretty-prints as "25g 0s 0c".

Cross-references back to WSKL — skill entries reference costId
here for the tiered training schedule. nextTrainable(currentSkill,
characterLevel) is the engine helper that returns the lowest-rank
tier a character qualifies for and hasn't capped yet — used by
trainer NPCs to populate their offered-skill list.

Three preset emitters: --gen-scs (6 profession tiers), --gen-scs-
weapon (5 weapon skill tiers), --gen-scs-riding (5 riding tiers
with canonical gold costs).

Validation enforces id+name presence, costKind 0..4, no duplicate
ids, min<max range; warns on:
  - requiredLevel > 80 (unreachable at WotLK cap)
  - RidingSkill with requiredLevel < 20 (Apprentice canonically
    unlocks at 20)
  - Profession kind with copperCost=0 (every standard tier costs
    at least a copper — usually a config bug)

Wired through the cross-format table; WSCS appears automatically
in all 15 cross-format utilities. Format count 84 -> 85; CLI
flag count 1010 -> 1015.

tools/editor/cli_list_formats.cpp

@@ -109,6 +109,7 @@ constexpr FormatRow kFormats[] = {
     {"WSEF", ".wsef",  "spells",    "SpellEffect.Effect dispatch",      "Spell effect type catalog"},
     {"WAUR", ".waur",  "spells",    "SpellEffect.EffectAuraType",       "Spell aura type catalog"},
     {"WIQR", ".wiqr",  "items",     "Item quality tier colors+rules",   "Item quality tier catalog"},
+    {"WSCS", ".wscs",  "skills",    "SkillCostsData.dbc + train tiers", "Skill cost / training tier catalog"},
 
     // Additional pipeline catalogs without the alternating
     // gen/info/validate CLI surface (loaded by the engine