fix(ui-tui): clear sticky prompt when follow snaps to bottom

Renderer-driven follow-to-bottom was restoring the viewport to the tail without notifying ScrollBox subscribers, so StickyPromptTracker could stay stale-visible. Notify on render-time scroll/sticky changes and treat near-bottom as bottom for prompt hiding.

ui-tui/packages/hermes-ink/src/ink/components/ScrollBox.tsx

@@ -257,6 +257,7 @@ function ScrollBox({ children, ref, stickyScroll, ...style }: PropsWithChildren<
 
         if (el) {
           el.scrollTop ??= 0
+          el.notifyScrollChange = notify
         }
       }}
       style={{

ui-tui/packages/hermes-ink/src/ink/dom.ts

@@ -72,6 +72,7 @@ export type DOMElement = {
   scrollViewportHeight?: number
   scrollViewportTop?: number
   stickyScroll?: boolean
+  notifyScrollChange?: () => void
   // Set by ScrollBox.scrollToElement; render-node-to-output reads
   // el.yogaNode.getComputedTop() (FRESH — same Yoga pass as scrollHeight)
   // and sets scrollTop = top + offset, then clears this. Unlike an

ui-tui/packages/hermes-ink/src/ink/render-node-to-output.ts

@@ -761,6 +761,7 @@ function renderNodeToOutput(
         // active text selection by the same delta (native terminal behavior:
         // view keeps scrolling, highlight walks up with the text).
         const scrollTopBeforeFollow = node.scrollTop ?? 0
+        const stickyBeforeFollow = node.stickyScroll
 
         const sticky = node.stickyScroll ?? Boolean(node.attributes['stickyScroll'])
 
@@ -863,6 +864,10 @@ function renderNodeToOutput(
           scrollDrainNode = node
         }
 
+        if ((node.scrollTop ?? 0) !== scrollTopBeforeFollow || node.stickyScroll !== stickyBeforeFollow) {
+          node.notifyScrollChange?.()
+        }
+
         scrollTop = clamped
 
         if (content && contentYoga) {