Add [mounted]/[nomounted] and [standing]/[sitting] conditionals

Back them with ClassicAPI IsMounted() and UnitStandState("player").
mounted/nomounted are player mount state; standing = stand state 0,
sitting = any non-standing pose (its complement). Player-only, registered
in Keywords, BOOLEAN_CONDITIONALS, and STATIC_CONDITIONALS like [stealth].

ClassicAPI.lua

@@ -182,6 +182,17 @@ function API.IsSwimming()
     return IsSwimming() and true or false
 end
 
+-- True if the player is currently mounted.
+function API.IsMounted()
+    return IsMounted() and true or false
+end
+
+-- Player's stand state: 0 = standing, non-zero = sitting/sleeping/kneeling/etc.
+-- (see UnitStandState). Player-only.
+function API.GetPlayerStandState()
+    return UnitStandState("player") or 0
+end
+
 --------------------------------------------------------------------------------
 -- Cursor
 --------------------------------------------------------------------------------

Conditionals.lua

@@ -5608,6 +5608,23 @@ CleveRoids.Keywords = {
         return not CleveRoids.ClassicAPI.IsStealthed()
     end,
 
+    mounted = function(conditionals)
+        return CleveRoids.ClassicAPI.IsMounted()
+    end,
+
+    nomounted = function(conditionals)
+        return not CleveRoids.ClassicAPI.IsMounted()
+    end,
+
+    standing = function(conditionals)
+        return CleveRoids.ClassicAPI.GetPlayerStandState() == 0
+    end,
+
+    -- Any non-standing pose (sit / chair / sleep / kneel)
+    sitting = function(conditionals)
+        return CleveRoids.ClassicAPI.GetPlayerStandState() ~= 0
+    end,
+
     casting = function(conditionals)
         if type(conditionals.casting) ~= "table" then return CleveRoids.CheckSpellCast(conditionals.target, "") end
         return Or(conditionals.casting, function (spell)
@@ -9182,6 +9199,7 @@ CleveRoids.STATIC_CONDITIONALS = {
     combat = true, nocombat = true, ic = true, ooc = true,
     zone = true, nozone = true,
     stealth = true, nostealth = true, stl = true, nostl = true,
+    mounted = true, nomounted = true, standing = true, sitting = true,
     form = true, noform = true, stance = true, nostance = true,
     equipped = true, noequipped = true, eq = true, noeq = true,
     set = true, noset = true,

Core.lua

@@ -121,6 +121,10 @@ local BOOLEAN_CONDITIONALS = {
     nocombat = true,
     stealth = true,
     nostealth = true,
+    mounted = true,
+    nomounted = true,
+    standing = true,
+    sitting = true,
     channeled = true,
     nochanneled = true,
     checkchanneled = true,