Perf: Eliminate first-scroll unresponsiveness

TEST.md

@@ -34,3 +34,4 @@
   - Successfully decoupled dynamic UI states (like `.dt-cell-selected`) from the declarative binding framework. We now use manual DOM manipulation (`applySelectionUI`) during `refresh` to sync states.
   - This manual sync completely prevents "Dependency Floods" where scrolling would trigger heavy `$class` evaluations on every cell. We maintained the Zero-Scan status while supporting rich interactions.
   - Fixed a VirtualScroll jumping bug at row 70+ by re-enabling `onItemUpdate` so VirtualScroll correctly learns the 40px row height instead of using its 32px default.
+  - **Scroll Initiation Fix**: Removed the `setTimeout` wrapper around `vs.init` during `reset`. Previously, the first scroll often hit a "blank wall" because VirtualScroll's internal metrics hadn't finished initializing when the user made their first swift scroll motion. Synchronous initialization resolved this completely.

src/scroll.js

@@ -30,11 +30,9 @@ export const createScrollManager = (container, state, onRenderedListChange) => {
         reset: (list) => {
             state._listStartIndex = 0;
             state._renderedList = vs.reset(list, scrollEl || container) || [];
-            setTimeout(() => { 
-                if (state.list === list) {
-                    vs.init(list, refresh);
-                }
-            });
+            if (state.list === list) {
+                vs.init(list, refresh);
+            }
         },
         updateRowHeight: (index, node) => {
             // Restore this call so VirtualScroll can learn the actual height