Add an AI column that researches every row

Adds a smart column to the list and starts its first run. Every covered row is researched from prompt by the chosen engine and billed at that engine's per-row credit rate; the run is charged up front, so the call answers 402 INSUFFICIENT_CREDITS when your balance cannot cover it and nothing is created. runOn bounds the first run (first_1 … first_1000 rows in the list's current order, or all) and filters narrows the rows it may cover; run the column again later (POST …/smart-columns/{columnId}/rerun with mode: new_only) to fill the rest. engine: deep_research uses the multi-provider Deep Research pipeline at a higher per-row rate and is the only engine that accepts a providerIds restriction (provider slugs from GET /business/research/providers); standard (default) is the per-row web-research agent. The name must be free on the list (409 COLUMN_NAME_TAKEN) and must not be a reserved built-in column name (422 COLUMN_NAME_RESERVED), and a filter that matches no row is rejected with 422 NO_ROWS_TO_RESEARCH before anything is charged. The call is asynchronous: it answers 202 with the run's jobId and the new column. Poll GET /business/lists/{listId}/smart-columns/{jobId}/status until status is completed, partially_completed, failed or cancelled, then read the values from GET /business/lists/{listId}/rows (columnValues[columnId]) and each cell's sources from the provenance endpoint.

Errors:

• 402 INSUFFICIENT_CREDITS — Your credit balance cannot cover the run (covered rows × the engine's per-row rate); nothing was started or charged.
• 404 LIST_NOT_FOUND — No list with that id belongs to you.
• 409 COLUMN_NAME_TAKEN — A column with this name already exists on the list.
• 422 COLUMN_NAME_RESERVED — The name is one of the reserved built-in column names (name, first name, last name, job title, company, email, phone …).
• 422 PROVIDERS_NOT_SUPPORTED — providerIds was sent for the standard engine; only a deep_research column can be restricted to specific providers.
• 422 NO_ROWS_TO_RESEARCH — No row on the list matches filters, so there is nothing to research and nothing was charged.
• 422 INVALID_REQUEST — CRM rejected the column definition for a reason with no more specific code.
• 422 VALIDATION_FAILED — The path, query or body failed validation; param names the offending field and message says why.
• 429 RATE_LIMITED — More than 120 requests per minute or 10,000 per day on the lists bucket, which every /business/lists endpoint shares; retry after Retry-After.
• 500 UNEXPECTED_ERROR — The request could not be completed; quote request_id to support.

Requires one of the following token scopes: lists.