feat(editor): add WSCT (Spell Cast Time Index) open catalog format

Companion to WSRG: open replacement for SpellCastTimes.dbc plus
the per-spell castTime fields in Spell.dbc. Defines categorical
cast-time buckets (Instant 0ms / FastCast 1s / MediumCast 1.5s /
LongCast 3s) that thousands of spells reference instead of each
embedding their own ms count. Together WSRG and WSCT let the
spell engine resolve "Frostbolt's range bucket = id 3" and
"Frostbolt's cast time bucket = id 5" with two table reads
instead of duplicating per-rank data.

Cast time can scale with character level via perLevelMs (a rank-1
spell at 1000ms can grow to 2200ms at lvl 60), then the bucket
result is clamped to [minCastMs, maxCastMs] before haste is
applied. resolveAtLevel() does the math for engine consumers.

Three preset emitters: --gen-sct (4 baseline buckets),
--gen-sct-channel (3 channeled-spell durations), --gen-sct-ramp
(4 level-scaled buckets with non-zero perLevelMs). Validation
catches negative baseCastMs, min>max, duplicate ids, warns on
Instant kind with non-zero base (cast bar would still show), and
errors on Channel kind with zero base (would tick once and end).

Wired through the cross-format table; WSCT appears automatically
in all 9 cross-format utilities. Format count 68 -> 69; CLI flag
count 892 -> 897.

tools/editor/cli_format_table.cpp

@@ -71,6 +71,7 @@ constexpr FormatMagicEntry kFormats[] = {
     {{'W','U','M','V'}, ".wumv",  "stats",     "--info-wumv",      "Unit movement type catalog"},
     {{'W','Q','S','O'}, ".wqso",  "quests",    "--info-wqso",      "Quest sort / category catalog"},
     {{'W','S','R','G'}, ".wsrg",  "spells",    "--info-wsrg",      "Spell range bucket catalog"},
+    {{'W','S','C','T'}, ".wsct",  "spells",    "--info-wsct",      "Spell cast time 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"},