Mod naming rule and engine UI in engine mods

Mods are renamed by role (shell2d_base, menu_base, ui_base, live2d_base,
editor_tools, cthangover_story, cthangover_murakami, cthangover_party) and
every reference follows. Engine UI prefabs (dialog, answers, message, game
menu, inventory, map, skills) and their panel entries moved out of the story
mod into the subsystem mods; the card_novel and vn_starter_novel collections
are removed.

src/UI/Executable/ScenarioEvent.cs

@@ -22,7 +22,7 @@ namespace Cthangover.Mods.Dialog.Executable
     /// dialog queue. Resolves the scenario path via convention: if ScenarioPath
     /// is set, uses that; otherwise searches all mods for a matching file name
     /// derived from the class name (stripping "Event" suffix), with a fallback
-    /// to res://mods/visual_novel_core/scenarios/. CustomMappings allows code to register
+    /// to res://mods/cthangover_story/scenarios/. CustomMappings allows code to register
     /// arbitrary class-to-path bindings for mod-provided scenarios. Supports
     /// inline ScenarioText for embedded scenarios that don't need a separate
     /// file. Checks conditions through ScenarioCondition.Evaluate before triggering.