Put in an amount of effort that you consider professional at work (by which I mean, put in enough effort that you're proud of yourself, even if you're less productive than you'd consider ideal for someone specialising in what they need). Use React on side projects. Look for better opportunities, and be more picky and curious about the actual work you'll be doing. You owe them no more loyalty or accommodation than they've shown you by misleadingly recruiting you.
Chalk it all up to career learning... Try not to get too personally invested or discouraged.
Chalk it all up to career learning... Try not to get too personally invested or discouraged.