fix(tui): default session sidebar to auto (#13046)

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

@@ -141,7 +141,7 @@ export function Session() {
   })
 
   const dimensions = useTerminalDimensions()
-  const [sidebar, setSidebar] = kv.signal<"auto" | "hide">("sidebar", "hide")
+  const [sidebar, setSidebar] = kv.signal<"auto" | "hide">("sidebar", "auto")
   const [sidebarOpen, setSidebarOpen] = createSignal(false)
   const [conceal, setConceal] = createSignal(true)
   const [showThinking, setShowThinking] = kv.signal("thinking_visibility", true)