classicapi: two-tier version check + drop hardcoded github URLs

Splits the ClassicAPI version check into a hard floor (MIN, manual)
and a soft target (LATEST, pinned by the release workflow). Below MIN
pfUI disables itself entirely as before; between MIN and LATEST it
runs normally but fires a delayed chat nudge after PLAYER_LOGIN with
the available update. PLAYER_LOGIN handlers swap to
EventUtil.ContinueOnPlayerLogin so we don't have to spin a frame for
each branch.

URLs centralize on toc X-Website fields. pfUI.lua factors out
ClassicAPIReleaseUrl(version) sourcing from !!!ClassicAPI's metadata;
modules/gui.lua and libs/libdebuff.lua replace hardcoded
me0wg4ming/pfUI links with GetAddOnMetadata(pfUI.name, "X-Website")
lookups.

release.yml gains a pre-package step that queries ClassicAPI's latest
release tag, packs it (X*10000 + Y*100 + Z), and seds only the LATEST
line in pfUI.lua so the published zip ships with the correct soft
target.

libs/libdebuff.lua

@@ -226,7 +226,7 @@ StaticPopupDialogs["LIBDEBUFF_NAMPOWER_UPDATE"] = {
   hideOnEscape = 0,
   preferredIndex = 3,
   OnAccept = function()
-    pfUI.chat.urlcopy.CopyText("https://github.com/me0wg4ming/pfUI/wiki/How-to-install-nampower")
+    pfUI.chat.urlcopy.CopyText(GetAddOnMetadata(pfUI.name, "X-Website") .. "/wiki/How-to-install-nampower")
   end,
 }
 
@@ -239,7 +239,7 @@ StaticPopupDialogs["LIBDEBUFF_NAMPOWER_MISSING"] = {
   hideOnEscape = 0,
   preferredIndex = 3,
   OnAccept = function()
-    pfUI.chat.urlcopy.CopyText("https://github.com/me0wg4ming/pfUI/wiki/How-to-install-nampower")
+    pfUI.chat.urlcopy.CopyText(GetAddOnMetadata(pfUI.name, "X-Website") .. "/wiki/How-to-install-nampower")
   end,
 }