Spline parsing: remove Classic format fallback from the WotLK parser. The
PacketParsers hierarchy already dispatches to expansion-specific parsers
(Classic/TBC/WotLK/Turtle), so the WotLK parseMovementBlock should only
attempt WotLK spline format. The Classic fallback could false-positive when
durationMod bytes resembled a valid point count, corrupting downstream parsing.
Preload DBC caches: call loadSpellNameCache() and 5 other lazy DBC caches
during handleLoginVerifyWorld() on initial world entry. This moves the ~170ms
Spell.csv load from the first SMSG_SPELL_GO handler to the loading screen,
eliminating the mid-gameplay stall.
WMO portal culling: move per-instance portalVisibleGroups vector and
portalVisibleGroupSet to reusable member variables, eliminating heap
allocations per WMO instance per frame.
6f2c8962e5