feat(editor): add WSPC (Spell Power Cost) — completes spell-bucket five-pack

Open replacement for the per-spell power-cost fields in Spell.dbc
plus SpellPowerCost-related side tables. Defines categorical
power-cost buckets that spells reference (LowMana 5% / MediumMana
15% / HighMana 30% of caster max mana; fixed Rage-30 /
Energy-40 / Runic-30 / etc), so spells share cost metadata across
ranks instead of embedding per-rank cost numbers.

Completes the small lookup-bucket five-pack:
  WSRG — range bucket
  WSCT — cast time bucket
  WSDR — duration bucket
  WSCD — cooldown bucket
  WSPC — power cost bucket   (this catalog)

Five small integer ids per spell (range / cast / dur / cd / cost)
replace the dozens of duplicate per-rank fields that Blizzard's
Spell.dbc carries. Editing one bucket here retunes every spell
that references it — change LowMana from 5% to 4% and every
rank-1 bolt across every caster class becomes cheaper.

Cost can be flat (baseCost), per-level scaled (perLevelCost), or
percentage-of-max-power (percentOfBase) — the engine sums
whichever fields are non-zero. resolveCost(id, level, maxPower)
does the math. Twelve power types covering every WoW resource
(Mana / Rage / Focus / Energy / Happiness / Runic Power / Runes /
Soul Shards / Holy Power / Eclipse / Health / NoCost).

Three preset emitters: --gen-spc (4 baseline mana tiers),
--gen-spc-rage (4 fixed warrior rage costs including stance-locked
Whirlwind), --gen-spc-mixed (5 cross-class costs covering every
non-mana power type with refund-on-miss flag for energy).

Validation enforces id+name presence, powerType 0..11, no
duplicate ids; warns on percentOfBase outside [0,1] (would
overflow), NoCost type with non-zero cost fields, and non-NoCost
types with no cost set (would cast for free — easy bug to ship).

Wired through the cross-format table; WSPC appears automatically
in all 11 cross-format utilities. Format count 72 -> 73; CLI flag
count 922 -> 927.

tools/editor/cli_format_table.cpp

@@ -75,6 +75,7 @@ constexpr FormatMagicEntry kFormats[] = {
     {{'W','S','D','R'}, ".wsdr",  "spells",    "--info-wsdr",      "Spell duration bucket catalog"},
     {{'W','S','C','D'}, ".wscd",  "spells",    "--info-wscd",      "Spell cooldown category catalog"},
     {{'W','C','E','F'}, ".wcef",  "creatures", "--info-wcef",      "Creature / pet family catalog"},
+    {{'W','S','P','C'}, ".wspc",  "spells",    "--info-wspc",      "Spell power cost bucket 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"},