tui: improve responsive layout by hiding header/footer when sidebar is visible (#7365)

Author: thdxr

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -887,7 +887,7 @@ export function Session() {
 <boxflexDirection="row">
 <boxflexGrow={1}paddingBottom={1}paddingTop={1}paddingLeft={2}paddingRight={2}gap={1}>
 <Showwhen={session()}>
-<Showwhen={!sidebarVisible()}>
+<Showwhen={!sidebarVisible()||!wide()}>
 <Header/>
 </Show>
 <scrollbox
@@ -1028,9 +1028,6 @@ export function Session() {
 sessionID={route.sessionID}
 />
 </box>
-<Showwhen={!sidebarVisible()}>
-<Footer/>
-</Show>
 </Show>
 <Toast/>
 </box>