Fix armor stat in character stats panel via UNIT_FIELD_RESISTANCES

The character stats panel was showing Armor: 0 because summing armor
from item query responses is fragile (depends on correct BuyCount/damage
block parsing). Instead, read the server-authoritative total armor
directly from UNIT_FIELD_RESISTANCES (physical resistance, index 0)
in the player entity update fields.

Added UNIT_FIELD_RESISTANCES to the UF enum and all four expansion
JSON files with correct wire indices:
  WotLK 3.3.5a: 99   (NPC_FLAGS=82 + emotestate + stat×5 + posstat×5 + negstat×5)
  TBC 2.4.3:   185   (NPC_FLAGS=168 + same relative layout)
  Classic 1.12: 154  (NPC_FLAGS=147 + emotestate + stat×5, no posstat/negstat)
  Turtle WoW:  154   (same as Classic)

Stats panel uses server armor when > 0, falls back to summed item-query
armor otherwise. Armor rating resets to 0 on world entry and is updated
from both CREATE_OBJECT and VALUES update blocks.

include/game/update_field_table.hpp

@@ -32,6 +32,7 @@ enum class UF : uint16_t {
     UNIT_FIELD_AURAS,           // Start of aura spell ID array (48 consecutive uint32 slots, classic/vanilla only)
     UNIT_NPC_FLAGS,
     UNIT_DYNAMIC_FLAGS,
+    UNIT_FIELD_RESISTANCES,   // Physical armor (index 0 of the resistance array)
     UNIT_END,
 
     // Player fields