Core/Player: Fix MAX_TITLE_INDEX calculation for title mask (#461)

* Core/Player: Fix MAX_TITLE_INDEX calculation for title mask

* Core/Player: Replace sizeof-based bit calculation with explicit 64

src/server/game/Entities/Player/Player.cpp

@@ -24916,7 +24916,9 @@ bool Player::isTotalImmune() const
 
 bool Player::HasTitle(uint32 bitIndex) const
 {
-    if (bitIndex > MAX_TITLE_INDEX)
+    // bitIndex is zero-based inside PLAYER__FIELD_KNOWN_TITLES.
+    // MAX_TITLE_INDEX is the total number of available bits (valid range: [0, MAX_TITLE_INDEX)).
+    if (bitIndex >= MAX_TITLE_INDEX)
         return false;
 
     uint32 fieldIndexOffset = bitIndex / 32;