compat(lua50): replace % modulo operator with math.mod shim

Lua 5.0 (Vanilla 1.12) has no % operator outside string formatting; it is a
parse error. Route the 9 arithmetic modulo sites through the existing math.mod
shim (Compat/Compat.lua) so the addon parses on 5.0 through Retail.

Sites: QuestieDB daily/weekly flag tests, QuestieEvent DMF cycle math,
QuestieLearner GUID/flag math, QuestiePlayer race/class flag tests.

Database/Corrections/QuestieEvent.lua

@@ -178,7 +178,7 @@ _GetDarkmoonFaireLocationEra = function(currentDate)
     local monthOffset = (currentDate.year - baseInfo.year) * 12 + (currentDate.month - baseInfo.month)
     local firstWeekday = C_Calendar.GetMonthInfo(monthOffset).firstWeekday
 
-    local eventLocation = (currentDate.month % 2) == 0 and DMF_LOCATIONS.MULGORE or DMF_LOCATIONS.ELWYNN_FOREST
+    local eventLocation = math.mod(currentDate.month, 2) == 0 and DMF_LOCATIONS.MULGORE or DMF_LOCATIONS.ELWYNN_FOREST
 
     local dayOfMonth = currentDate.monthDay
     if firstWeekday == 1 then
@@ -230,7 +230,7 @@ _GetDarkmoonFaireLocationSoD = function(currentDate)
     local eventDuration = initialEndDate - initialStartDate
     local timeSinceStart = currentDate - initialStartDate
 
-    local positionInCurrentCycle = timeSinceStart % (eventDuration * 2) -- * 2 because the event repeats every two weeks
+    local positionInCurrentCycle = math.mod(timeSinceStart, (eventDuration * 2)) -- * 2 because the event repeats every two weeks
 
     local isEventActive = positionInCurrentCycle < eventDuration
 
@@ -240,7 +240,7 @@ _GetDarkmoonFaireLocationSoD = function(currentDate)
 
     local weeksSinceStart = math.floor(timeSinceStart / eventDuration)
 
-    if weeksSinceStart % 4 == 0 then
+    if math.mod(weeksSinceStart, 4) == 0 then
         return DMF_LOCATIONS.MULGORE
     else
         return DMF_LOCATIONS.ELWYNN_FOREST

Database/QuestieDB.lua

@@ -915,7 +915,7 @@ end
 function QuestieDB.IsDailyQuest(questId)
     local flags = QuestieDB.QueryQuestSingle(questId, "questFlags")
     -- test a bit flag: (value % (2*flag) >= flag)
-    return flags and (flags % QUEST_FLAGS_DAILY_X2) >= QUEST_FLAGS_DAILY
+    return flags and math.mod(flags, QUEST_FLAGS_DAILY_X2) >= QUEST_FLAGS_DAILY
 end
 
 ---@param questId number
@@ -923,7 +923,7 @@ end
 function QuestieDB.IsWeeklyQuest(questId)
     local flags = QuestieDB.QueryQuestSingle(questId, "questFlags")
     -- test a bit flag: (value % (2*flag) >= flag)
-    return flags and (flags % QUEST_FLAGS_WEEKLY_X2) >= QUEST_FLAGS_WEEKLY
+    return flags and math.mod(flags, QUEST_FLAGS_WEEKLY_X2) >= QUEST_FLAGS_WEEKLY
 end
 
 ---@param questId number

Modules/QuestieLearner.lua

@@ -3348,7 +3348,7 @@ local function GetIdAndTypeFromGUID(guid)
         if t then
             local low32 = tonumber(string.sub(guid, 11, 18), 16)
             if low32 then
-                local nid = low32 % 8388608
+                local nid = math.mod(low32, 8388608)
                 if nid > 0 then return nid, t end
             end
         end
@@ -3460,7 +3460,7 @@ end
 local function NpcFlagsHasQuestGiver(flags)
     if not flags then return false end
     -- bitwise AND for Lua 5.1 (no bit library guaranteed)
-    return math.floor(flags / NPC_FLAG_QUESTGIVER) % 2 == 1
+    return math.mod(math.floor(flags / NPC_FLAG_QUESTGIVER), 2) == 1
 end
 
 function QuestieLearner:OnMouseoverUnit()

Modules/QuestiePlayer.lua

@@ -100,13 +100,13 @@ end
 ---@return boolean
 function QuestiePlayer.HasRequiredRace(requiredRaces)
     -- test a bit flag: (value % (2*flag) >= flag)
-    return (not requiredRaces) or (requiredRaces == 0) or ((requiredRaces % playerRaceFlagX2) >= playerRaceFlag)
+    return (not requiredRaces) or (requiredRaces == 0) or (math.mod(requiredRaces, playerRaceFlagX2) >= playerRaceFlag)
 end
 
 ---@return boolean
 function QuestiePlayer.HasRequiredClass(requiredClasses)
     -- test a bit flag: (value % (2*flag) >= flag)
-    return (not requiredClasses) or (requiredClasses == 0) or ((requiredClasses % playerClassFlagX2) >= playerClassFlag)
+    return (not requiredClasses) or (requiredClasses == 0) or (math.mod(requiredClasses, playerClassFlagX2) >= playerClassFlag)
 end
 
 function QuestiePlayer:GetCurrentZoneId()