Keep the HubSpot product library in step with Stripe prices

**Objective:** Make the HubSpot product library hold one product for each active Stripe price in currency `{currency}` (default usd) on up to `{max-records}` active Stripe products (default 50, optionally only names containing `{product-name}`), matched by the Stripe price id. Nothing is written until the user confirms.

**Step 1: Read products and prices from Stripe**

Call `stripe-get-product` with `active` set to true, `name.contains` set to `{product-name}` if given and `max-records` set to `{max-records}` (50 if empty). Keep `product-id`, `name` and `description`. For each product, call `stripe-get-price` with `product-id` set to it and `active` set to true, and keep prices whose `currency` is `{currency}` (usd if empty), compared case-insensitively. Keep `price-id`, `unit-amount`, `type`, `recurring-interval`, `recurring-interval-count`, `recurring-usage-type`, `billing-scheme` and `nickname`.

Prices with `recurring-usage-type` metered or `billing-scheme` tiered have no single unit price: list them and leave them out.

**Step 2: Work out the HubSpot values**

* `sku`: the Stripe `price-id`. This is the join.
* `name`: the product `name`; when the product has more than one kept price, add the `nickname` or the interval in brackets, for example "Pro (annually)".
* `price`: `unit-amount` divided by 100 (do not divide for zero-decimal currencies such as JPY).
* `billing-frequency`: month with count 1 = monthly, 3 = quarterly, 6 = per_six_months; year with count 1 = annually, 2 = per_two_years, 3 = per_three_years; week with count 1 = weekly, 2 = biweekly. A one_time price or any other combination leaves it empty.

**Step 3: Compare with the HubSpot product library**

For each price, call `hubspot-get-products` with `sku` set to the `price-id`.

* No match: the price goes on the create list.
* One match: compare `name`, `unit-price` and `billing-frequency`. Any difference puts it on the update list with before and after values.
* More than one match: list the duplicates and leave them alone.

Also call `hubspot-get-products` with `name` set to each product name; a product found by name but not by SKU is listed as a possible match so the user can avoid a duplicate.

**Step 4: Confirm**

Show products to create (name, SKU, price, billing frequency), products to update (record-id, field, current value, new value), possible matches and skipped prices with the reason. Ask for an explicit yes and offer to exclude rows. Do not continue without a yes.

**Step 5: Write and verify**

For each confirmed new price, call `hubspot-add-product` once with `name`, `sku`, `price`, `billing-frequency` when it has one and `description` from the Stripe product. For each confirmed change, call `hubspot-update-product` once with `id` set to the HubSpot `record-id` and only the fields that differ. Then call `hubspot-get-products` with `sku` set to each price id and confirm the values. Report created, updated, failed and skipped rows.

**Rules & Guidelines:**

* `stripe-get-product` and `stripe-get-price` are on the stripe server; `hubspot-get-products`, `hubspot-add-product` and `hubspot-update-product` are on the hubspot server.
* The only write tools allowed are `hubspot-add-product`, once per confirmed new price, and `hubspot-update-product`, once per confirmed change, both only after the confirmation in Step 4. Call no other hubspot-add, hubspot-update, hubspot-rename, hubspot-remove, hubspot-subscribe, hubspot-unsubscribe or hubspot-import tool.
* The stripe server has no write tools; only the stripe read tools named here are used, and nothing is charged, refunded or sent to the customer.
* Never convert between currencies. Do not set `cost`, `product-type` or `owner-id`.

**Validation:**

* If no active price exists in `{currency}`, say so and stop.
* If the user declines or does not answer, stop with nothing written.
* If a product does not show the new values on re-read, say so and do not retry blindly.