tui: fix agent cycling and prompt metadata polish (#23115)

packages/opencode/src/cli/cmd/tui/util/signal.ts

@@ -8,20 +8,23 @@ export function createDebouncedSignal<T>(value: T, ms: number): [Accessor<T>, Sc
 
 export function createFadeIn(show: Accessor<boolean>, enabled: Accessor<boolean>) {
   const [alpha, setAlpha] = createSignal(show() ? 1 : 0)
+  let revealed = show()
 
   createEffect(
-    on([show, enabled], ([visible, animate], previous) => {
+    on([show, enabled], ([visible, animate]) => {
       if (!visible) {
         setAlpha(0)
         return
       }
 
-      if (!animate || !previous) {
+      if (!animate || revealed) {
+        revealed = true
         setAlpha(1)
         return
       }
 
       const start = performance.now()
+      revealed = true
       setAlpha(0)
 
       const timer = setInterval(() => {