slash: write SLASH_* keys to _G inside module bodies

pfUI module bodies run under pfUI.env (setfenv in LoadModule), which
proxies reads to _G via __index but has no __newindex. Bare
"SLASH_FOO = ..." assignments therefore land on pfUI.env, not on _G,
and WoW's slash dispatcher reads _G.SLASH_* directly — so the slash
command never registered. SlashCmdList[KEY] assignments happened to
work because the table is read first (falls through), then the key
write hits the real global table.

/pfunitxp, /clickthrough, /ct, /disenchantall, /dea — all silently
broken until now. Fixed by prefixing SLASH_* writes with _G.

modules/nampower.lua

@@ -150,8 +150,8 @@ pfUI:RegisterModule("nampower", function ()
 
   -- /disenchantall slash command (DisenchantAll is Nampower-provided)
   if DisenchantAll then
-    SLASH_PFDISENCHANTALL1 = "/disenchantall"
-    SLASH_PFDISENCHANTALL2 = "/dea"
+    _G.SLASH_PFDISENCHANTALL1 = "/disenchantall"
+    _G.SLASH_PFDISENCHANTALL2 = "/dea"
     SlashCmdList["PFDISENCHANTALL"] = function()
       DisenchantAll()
       DEFAULT_CHAT_FRAME:AddMessage("|cff33ffccpfUI|r: Disenchanting all eligible items...")

modules/superwow.lua

@@ -166,8 +166,8 @@ pfUI:RegisterModule("superwow", function ()
     end
 
     -- Add slash command for clickthrough toggle
-    SLASH_PFCLICKTHROUGH1 = "/clickthrough"
-    SLASH_PFCLICKTHROUGH2 = "/ct"
+    _G.SLASH_PFCLICKTHROUGH1 = "/clickthrough"
+    _G.SLASH_PFCLICKTHROUGH2 = "/ct"
     SlashCmdList["PFCLICKTHROUGH"] = function()
       local enabled = pfUI.api.ToggleClickthrough()
       DEFAULT_CHAT_FRAME:AddMessage("|cff33ffccpfUI|r: Clickthrough mode " .. (enabled and "|cff00ff00enabled|r" or "|cffff0000disabled|r"))

modules/unitxp.lua

@@ -352,7 +352,7 @@ pfUI:RegisterModule("unitxp", function ()
   end
 
   -- Debug command to test UnitXP indicators
-  SLASH_PFUNITXP1 = "/pfunitxp"
+  _G.SLASH_PFUNITXP1 = "/pfunitxp"
   SlashCmdList["PFUNITXP"] = function()
     local chat = DEFAULT_CHAT_FRAME
     chat:AddMessage("|cff33ffccpfUI|r: UnitXP Indicator Debug")