Core/Player: Fix MAX_TITLE_INDEX calculation for title mask

Author: gonzo1247

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;

src/server/game/Entities/Player/Player.h

@@ -479,8 +479,11 @@ static_assert((PLAYER_FIELD_BYTES_2_OFFSET_OVERRIDE_SPELLS_ID & 1) == 0, "PLAYER
 
 constexpr uint8 PLAYER_BYTES_2_OVERRIDE_SPELLS_UINT16_OFFSET = PLAYER_FIELD_BYTES_2_OFFSET_OVERRIDE_SPELLS_ID / 2;
 
-constexpr uint8 KNOWN_TITLES_SIZE = 4;
-constexpr uint32 MAX_TITLE_INDEX = KNOWN_TITLES_SIZE * sizeof(uint64); // 4 uint64 fields
+// PLAYER__FIELD_KNOWN_TITLES consists of 4 uint64 blocks (64 bits each).
+// Total available title bits = KNOWN_TITLES_SIZE * 64.
+constexpr uint32 KNOWN_TITLES_SIZE = 4;
+constexpr uint32 BITS_PER_TITLE_BLOCK = sizeof(uint64) * 8;
+constexpr uint32 MAX_TITLE_INDEX = KNOWN_TITLES_SIZE * BITS_PER_TITLE_BLOCK;
 
 // used in PLAYER_FIELD_BYTES values
 enum PlayerFieldByteFlags