fix(tui): fail fast on invalid session startup (#23837)

packages/opencode/src/cli/cmd/tui/attach.ts

@@ -3,6 +3,8 @@ import { UI } from "@/cli/ui"
 import { tui } from "./app"
 import { win32DisableProcessedInput, win32InstallCtrlCGuard } from "./win32"
 import { TuiConfig } from "@/cli/cmd/tui/config/tui"
+import { errorMessage } from "@/util/error"
+import { validateSession } from "./validate-session"
 
 export const AttachCommand = cmd({
   command: "attach <url>",
@@ -65,6 +67,20 @@ export const AttachCommand = cmd({
         return { Authorization: auth }
       })()
       const config = await TuiConfig.get()
+
+      try {
+        await validateSession({
+          url: args.url,
+          sessionID: args.session,
+          directory,
+          headers,
+        })
+      } catch (error) {
+        UI.error(errorMessage(error))
+        process.exitCode = 1
+        return
+      }
+
       await tui({
         url: args.url,
         config,