docs: the token API now serves pool typeAndVersion and finality

[aelmanaa]

This pull request updates the API documentation for the /tokens endpoints to clarify how pool information is represented and retrieved. The changes provide more detail about the fields available in the token detail route, including new information about pool finality and the distinction between authoritative and informational data.

API documentation improvements:

• Clarified that the token detail route now describes the pool with three fields: pool.typeAndVersion (the contract's string), pool.type (API enum), and pool.version (version number or null for dev builds).
• Added documentation for the new pool.finality field, which reports the allowed-finality config as read at indexing time.
• Explained that these pool fields are informational and may lag behind actual on-chain config, emphasizing that authoritative data is read directly from the pool contract.
• Specified that the list route does not include pool fields even with expand=true, and group members only carry basic identifying information.