Enhance SYSTEM_PROMPT in enrich_product.py to emphasize the importance of weight extraction

- Added detailed instructions to the SYSTEM_PROMPT regarding the critical nature of weight in grams for product cataloging.
- Specified guidelines for sourcing weight information from various resources and emphasized conversion from other units.

Author: maplethorpej

app/tasks/enrich_product.py

@@ -186,6 +186,11 @@ def ai_complete(system: str, user: str, tools: list | None = None, max_retries:
     "From the best available product page(s), extract:\n"
     "- A product URL (prefer the manufacturer's page if available, otherwise use a retail page)\n"
     "- The listed weight and any other specs (R-value, volume, packed size, temperature rating, etc.)\n\n"
+    "WEIGHT IS CRITICAL: Weight in grams is the single most important spec for our catalog. "
+    "You MUST make every effort to find it. Check the manufacturer's spec table, the product "
+    "page details, retail listings (REI, Amazon), and review sites. If weight is listed in "
+    "oz or lb, convert to grams. Only set weight_grams to null as a last resort when the "
+    "product genuinely has no published weight (e.g. consumables sold by food weight, not gear weight).\n\n"
     "IMPORTANT: A variant is a meaningful product option like size (S/M/L/Regular/Long), color, gender, "
     "or volume capacity. Weight measurements (e.g. \"690g\", \"14oz\", \"2lb\"), dimensions, or other specs "
     "that appear in the variant field are NOT real variants. If the provided variant is just a weight or "