fix(robotoff): handle 502 errors with user-friendly message in nutrient extraction

[Mounika-max-348]

What

• Added error handling for 502 (Bad Gateway) errors in the Robotoff API
• Updated insights() and questionsByProductCode() in robotoff.ts to throw a meaningful error when the API returns a non-OK response
• Updated the robotoff-nutrient-extraction component to display a user-friendly message when Robotoff is unavailable (502 error) instead of showing a raw error

Screenshot

Fixes bug(s)

• Handle Robotoff 502 errors inside Nutrition Game web-component #386

Part of

• Handle Robotoff 502 errors inside Nutrition Game web-component #386

[vercel]

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[Mounika-max-348]

Hi @teolemon! I've fixed issue #386 by adding 502 error handling in robotoff.ts and displaying a user-friendly message in the nutrient extraction component when Robotoff is unavailable. Please review and let me know if any changes are needed. 🙏