finish IsInRaid sweep across remaining "raid count > 0" sites

Three more `if GetNumRaidMembers() > 0 then` raid-vs-party branches
switched to `if IsInRaid()`. Same intent, named helper. Repo is now
clean of the legacy idiom (verified with a final grep).

Loops that actually need the count (`for i = 1, GetNumRaidMembers() do
GetRaidRosterInfo(i)`) keep the call — only the boolean form changes.

libs/libpredict.lua

@@ -190,7 +190,7 @@ pfUI.libdebuff_spell_start_self_hooks["libpredict"] = function(spellId, casterGu
       -- selfcast (ALT) = player, otherwise = current target
       -- Use this to find the correct group to heal
       local pohTarget = target or player
-      if GetNumRaidMembers() > 0 then
+      if IsInRaid() then
         -- Raid: find pohTarget's subgroup and heal only those members
         -- (Turtle WoW changed PoH to heal the target's group, not the caster's group)
         local targetGroup
@@ -299,7 +299,7 @@ pfUI.libdebuff_spell_start_other_hooks["libpredict"] = function(spellId, casterG
 
   -- Prayer of Healing: heal entire subgroup of the target
   if spellName == PRAYER_OF_HEALING then
-    if GetNumRaidMembers() > 0 then
+    if IsInRaid() then
       local targetGroup
       for i = 1, GetNumRaidMembers() do
         local rname, _, subgroup = GetRaidRosterInfo(i)

modules/turtle-wow.lua

@@ -47,7 +47,7 @@ pfUI:RegisterModule("turtle-wow", function ()
     -- Check if pfUI is handling group or raid for the current situation
     local function pfUIHandlesGroupOrRaid()
       local disabled = C["disabled"] or {}
-      if GetNumRaidMembers() > 0 then
+      if IsInRaid() then
         if not C.unitframes.raid then return false end
         -- Hide Turtle frames if: pfUI raid module is active, OR player disabled visibility
         if disabled["raid"] == "1" then