Missing API for fetching all cards in a custom column

[mattbnz]

As far as I can tell there is currently no API support for fetching all cards in a column - existing API clients (e.g. fizzy-cli) are forced to fetch all cards on a board and then filter client side when the column desired is not one of the built-in "indexed_by values: https://github.com/robzolkos/fizzy-cli/blob/master/internal/commands/card.go#L138

Looking at the code seems to confirm that the /cards API endpoint only supports the indexed_by values listed in the scope at https://github.com/basecamp/fizzy/blob/main/app/models/card.rb#L28

There is a separate /boards/BOARD_ID/columns/COLUMN_ID endpoint which the UI uses to fetch the HTML for a specific column, and which correctly renders the column-specific list of cards, but unfortunately for the JSON API it only returns the column metadata itself per: https://github.com/basecamp/fizzy/blob/main/app/views/boards/columns/show.json.jbuilder

In addition to just being inefficient to have to fetch ALL cards for a board in order to get the list of cards for a specific column, it seems very untidy to have the HTML/JSON results on the /boards/BOARD_ID/columns/COLUMN_ID show endpoint differ so dramatically!

My suggestion/request:

1. Fix /boards/BOARD_ID/columns/COLUMN_ID - to just be the column metadata (show) for both HTML and JSON
2. Add /boards/BOARD_ID/columns/COLUMN_ID/cards - (index) which returns HTML or JSON card listings of the cards in the column

Thoughts?