the addon arc: the AddOns folder opens

- benilla loads real 1.12 addons from Interface/AddOns — TOC, XML and Lua through one loader, with per-addon saved variables, Bindings.xml and the lifecycle events addons expect
- both AddOns screens are in: the character-select list with per-addon enable state, and the ESC menu's in-game list
- the API surface is measured, not guessed — a corpus harness runs hundreds of real 1.12 addons and ranks exactly which globals, templates and verbs they demand
- the Lua dialect is the client's own, read off the binary — 5.0 semantics with the 1.12 additions, and UI source files are bytes, not UTF-8

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/benilla-ui/src/script/scrollframe.rs

@@ -184,6 +184,10 @@ pub(super) fn install(lua: &Lua) -> mlua::Result<()> {
                 let range = scroll_range(&model, h);
                 (model.frame_id(h), range)
             };
+            // That forced resolve can have MOVED sizes — this method exists precisely because the
+            // caller just resized its content — so drain the queue before the range notify: the
+            // reference fires `OnSizeChanged` from `ApplyRect`, i.e. during the layout, not after.
+            event::fire_size_changes(lua);
             if let Err(e) = event::fire_widget_handler(
                 lua,
                 id,