Unify SavedVariables into two clean roots with one-time migration

Collapse all legacy/scattered SavedVariables from absorbed standalone
addons (FeedOMatic, ZHunter/zButtons, SmartAmmo, AutoQuest, AntiDaze,
AutoStrip, MinimapButton) into two persisted globals with clean per-module
nesting under .modules.<id>.

Migration engine (api/savedvariables.lua):
- MTH_SV_EnsureSchema() with schemaVersion gate, idempotent + non-destructive
- Per-module migrators map old locations -> canonical nested stores
- Driven by an ADDON_LOADED("MetaHunt") handler so it runs only AFTER WoW
  loads the real SavedVariables (fixes announce-every-session bug that ran
  the migration on empty pre-load defaults)
- One-time player-facing chat announce, gated on real legacy data present

Framework/config:
- core-framework InitSavedVariables no longer runs migration at file-load;
  unconditionally strips account-root module aliases
- config.lua stops re-creating root[module] aliases (was duplicating data
  onto disk); canonical store stays under .modules.<id>

Modules:
- feedomatic: bind FOM_* globals as runtime aliases into nested store,
  drop persisted duplicates and .legacy blob
- zhunter: ZHunterMod_Saved re-pointed at .modules.zhunter
- smartammo/autoquest/antidaze/autostrip/minimapbutton read nested store

TOC trimmed to MTH_SavedVariables + MTH_CharSavedVariables only.
Profiles unchanged (already snapshot/apply the nested .modules structure).

Also includes pet-scan refinements: canonical pet key derivation and
level-independent pet signature (schema v3).

api/core-framework.lua

@@ -1187,8 +1187,6 @@ function MTH:InitSavedVariables()
 	if not MTH_SavedVariables then
 		MTH_SavedVariables = {
 			modules = {},
-			feedomatic = {},
-			zhunter = {},
 		}
 	end
 
@@ -1198,12 +1196,6 @@ function MTH:InitSavedVariables()
 	if not MTH_SavedVariables.moduleStates then
 		MTH_SavedVariables.moduleStates = {}
 	end
-	if not MTH_SavedVariables.modules.feedomatic then
-		MTH_SavedVariables.modules.feedomatic = MTH_SavedVariables.feedomatic or {}
-	end
-	if not MTH_SavedVariables.modules.zhunter then
-		MTH_SavedVariables.modules.zhunter = MTH_SavedVariables.zhunter or {}
-	end
 	if type(MTH_SavedVariables.messages) ~= "table" then
 		MTH_SavedVariables.messages = {}
 	end
@@ -1215,9 +1207,6 @@ function MTH:InitSavedVariables()
 		end
 	end
 
-	MTH_SavedVariables.feedomatic = MTH_SavedVariables.modules.feedomatic
-	MTH_SavedVariables.zhunter = MTH_SavedVariables.modules.zhunter
-
 	if not MTH_CharSavedVariables then
 		MTH_CharSavedVariables = {}
 	end
@@ -1271,6 +1260,24 @@ function MTH:InitSavedVariables()
 			end
 		end
 	end
+
+	-- NOTE: the legacy/scattered SavedVariables consolidation (MTH_SV_EnsureSchema)
+	-- is intentionally NOT called here. InitSavedVariables also runs at file-load time
+	-- (before WoW has loaded the SV file from disk), when the roots are still empty
+	-- defaults. Running the migration there operated on throwaway tables and made it
+	-- re-announce every session. The migration is now driven from an ADDON_LOADED
+	-- handler in api/savedvariables.lua, which fires once the real saved data exists.
+
+	-- Account-root module aliases must NEVER persist: the canonical stores live under
+	-- .modules.<id>. feedomatic/zhunter used to be mirrored here (config.lua alias +
+	-- InitSavedVariables seeds), which made WoW serialize a full DUPLICATE on disk.
+	-- Strip them unconditionally on every load — even after the one-shot migration gate
+	-- has closed — so any stray copy re-created by older code, or already sitting in an
+	-- on-disk file from a previous version, is removed.
+	if type(MTH_SavedVariables) == "table" then
+		MTH_SavedVariables.feedomatic = nil
+		MTH_SavedVariables.zhunter = nil
+	end
 end
 
 function MTH:GetModuleSavedVariables(name)