feat(modules): add Broadcast Filter to hide Ascension Autobroadcast spam

New Chatter module registers a ChatFrame message filter that suppresses chat
lines matching a configurable list (default: 'Ascension Autobroadcast'). Matches
case-insensitively against the message body and every string arg, so it catches
the named-channel autobroadcast where the label is the channel name, not the
body. Editable list in the module's options; enabled by default.

Chatter/Localization/enUS.lua

@@ -4,6 +4,12 @@ local AceLocale = LibStub:GetLibrary("AceLocale-3.0")
 local L = AceLocale:NewLocale("Chatter", "enUS", true)
 if not L then return end
 
+-- ./Modules/BroadcastFilter.lua
+L["Broadcast Filter"] = true
+L["Hidden broadcasts"] = true
+L["Hides chat lines from broadcast channels or senders. One entry per line; matching is a case-insensitive substring against the message and its channel/sender."] = true
+L["Suppresses spammy server broadcasts such as the Ascension Autobroadcast Discord nag."] = true
+
 -- ./Chatter.lua
 L["Chatter"] = true
 L["Standalone Config"] = true