Catalog feature updates on column fields

docs/INGESTION_API.md

@@ -507,6 +507,52 @@ But that stability is per `image_id`: change the product name and you get a new
 10. Deterministic Product Validation Gate
 11. Vector Embedding & Storage
 
+Stages 8 and 9 each run several enrichment steps internally; the stage count and
+numbering are unchanged.
+
+### What gets filled for a branded row, and how far to trust it
+
+The rules above for `Own Products` still hold — an unbranded row is stored as
+you sent it. A **branded** row is gap-filled, and every filled value records
+*how* it was arrived at in a `field_sources` map on the row, so nothing has to
+be taken on trust:
+
+| `method` | Means | Example |
+| --- | --- | --- |
+| `sourced` | a real value from a real external source | nutrients measured per 100 g, from Open Food Facts |
+| `derived` | computed from another field on the same row | `ean13` from `barcode`; `tax_amount` from your price |
+| `estimated` | a category-level or brand-level inference | the keyword nutrient list before a lookup succeeds |
+| `not_applicable` | cannot exist for this product, and should not | nutrition on a shampoo; an FSSAI *food* licence on a detergent |
+| `unknown` | we have not got it and have no source for it | an FSSAI licence for a brand not in the registry |
+
+Two consequences worth reading twice:
+
+- **`not_applicable` is not a gap.** Roughly 30% of a general FMCG catalog is
+  soap, shampoo and detergent. Those rows will never have nutrients or a health
+  score. Coverage percentages are reported against the *applicable* rows, so
+  they describe work remaining rather than work impossible.
+- **`barcode_verified: false` means the pack is not confirmed.** A barcode found
+  by name match against a brand's catalogue is a real GS1 code for that brand,
+  written to every size variant of the title. Good enough for catalog matching,
+  dedup and nutrition lookups; **not** good enough for logistics, invoicing, or
+  anything a scanner drives. Filter on it before relying on a barcode
+  commercially.
+
+Nothing is ever invented. There is no LLM anywhere in the nutrient, barcode,
+FSSAI or tax path, and a value that cannot be sourced or safely derived is left
+empty and labelled rather than guessed.
+
+### Barcodes arrive after the upload finishes
+
+Barcode and nutrition enrichment need the network, so they do **not** hold up
+your response. Ingestion returns as soon as the rows are stored; a background
+job then fetches each brand's catalogue and fills barcodes, nutrition and health
+scores over the following minutes. Its id is on the batch as `nutrition_job_id`
+and its progress is at `GET /api/admin/nutrition-intelligence/jobs/{job_id}`.
+
+So a row read immediately after a `200` may have no barcode yet and have one a
+few minutes later. That is expected, and re-reading is the only action needed.
+
 ### Limits
 
 | Limit | Value | Env var | Exceeded |