Alias [mouseuse] to [cursor] via a conditional alias table

Adds CleveRoids.conditionalAliases, applied in ParseMsg so a deprecated name
is rewritten to its current keyword before anything downstream (evaluation,
_groups) sees it. This is the mechanism for renamed modifiers, which -- unlike
predicates such as [stl] -> [stealth] -- have no Keywords function an alias
could simply point at.

[mouseuse] now resolves to [cursor], routing old macros through ClassicAPI's
C_Spell.CastAtCursor / C_Item.UseAtCursor. Drops the post-cast block that cast
normally and then faked a mouse click via CameraOrSelectOrMoveStart/Stop to
place the AoE circle, along with its workaround for that call spuriously
starting auto-attack.

MacroErrorChecker seeds VALID_CONDITIONALS from the alias table, so the old
names stay valid syntax without needing a placeholder ignoreKeywords entry.

Init.lua

@@ -187,11 +187,19 @@ CleveRoids.ignoreKeywords = {
     _operators    = true,  -- Metadata for AND/OR operator tracking
     _groups       = true,  -- Grouped conditional values for AND/OR evaluation
     multiscan     = true,  -- Processed before Keywords loop (target resolution)
-    mouseuse      = true,  -- Post-cast modifier: auto-click AOE targeting circle at cursor
     cursor        = true,  -- Modifier: place ground-target spell/item at cursor (CastAtCursor)
     stopattack    = true,  -- Post-cast modifier: stop autoattack after cast (CheapShot pattern)
 }
 
+-- Deprecated conditional names, rewritten to their current keyword in ParseMsg
+-- before anything downstream (evaluation, _groups) sees them. This is the path
+-- for renamed *modifiers* -- ignoreKeywords entries, which have no Keywords
+-- predicate that an alias could just point at the way [stl] does for [stealth].
+-- MacroErrorChecker also reads this table, so the old names stay valid syntax.
+CleveRoids.conditionalAliases = {
+    mouseuse = "cursor",  -- pre-ClassicAPI name, back when it clicked the AoE reticle
+}
+
 -- TODO: Localize?
 CleveRoids.countedItemTypes = {
     ["Consumable"]  = true,