fix

docs/category-formulas.md

@@ -78,6 +78,31 @@ go run ./cmd/formula-e2e -new-tenant -llm-base http://127.0.0.1:18767/v1
 `-llm-base` pins the provider for the run; without it the harness uses whatever
 `platformsettings.ResolveOpenAI` returns (admin DB setting first, then env).
 
+## Low-confidence categorisation fails the product
+
+The categorize model always answers with *some* id from the list, so a reply like
+`{"categoryId":"1","confidence":0.08}` is the model saying "I do not know". Taking
+it at face value files a camping chair under Generators and then drives that
+category's formula, producing confidently wrong copy.
+
+Below `processing.DefaultMinCategorizeConfidence` (**0.75**) the product fails with
+`ErrCategoryNotFound` and processing stops there — enhance is never called, so no
+credits and no provider cost are spent writing copy for a category nobody believes
+in. The same applies when the model returns an id outside the taxonomy.
+
+```
+processing: category rejected uid=1 confidence=0.08 min=0.75 reason=low_confidence
+processing: item failed ... err=product category could not be determined:
+            best match "1" scored 0.08, below the 0.75 minimum
+```
+
+The product lands in the job as `failed` with that message on
+`processing_job_products.error`, and `raw_products.processing_status = 'failed'`.
+
+Not gated: a category that came from the feed, vector or a prior run (categorize
+never runs), a model that reports no confidence at all, and AI-disabled plans.
+Override the floor per job with `StepPolicy.MinCategorizeConfidence`.
+
 ## Why enhance can still return feed copy
 
 In order of how often it bites: