Upload a skincare product image for AI-powered analysis. The endpoint performs three stages:

1. Image Analysis — Extracts product name, brand, category, ingredients, and description from the image using AI.
2. Inventory Search — Searches the Oyster catalog for a matching product by name and brand.
3. Suitability Analysis — Evaluates how well the product fits the authenticated user's skin profile (skin type, concerns, allergies, goals, preferences, and avoidances).

The response includes a fit score (0–100) and an "Oyster Thinks" section with a personalized message.
When the fit score is below 80, Oyster suggests 1–3 better alternatives from the catalog with personalized reasons.

The user ID is derived from the Bearer token — no userId parameter is needed.

Rate limit: 2 product scans per calendar month. Returns 429 when exceeded.
Users with unlimited_scans or unlimited_product_scans are exempt.