Change Slack bot dialog first step button from Create Bot to Next

Aligns with the guided multi-step flow — the bot creation happens
transparently when advancing, rather than feeling like a separate action.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bchapuis

apps/app/src/components/workflow/widgets/input/slack-bot-create-dialog.tsx

@@ -199,10 +199,10 @@ export function SlackBotCreateDialog({
                 {isSubmitting ? (
                   <>
                     <Spinner className="h-4 w-4 mr-1" />
-                    Creating...
+                    Connecting...
                   </>
                 ) : (
-                  "Create Bot"
+                  "Next"
                 )}
               </Button>
             </div>