findConversation resolves an exact public or private channel name or ID. Use
it when configuration contains a human-readable channel name but later actions
need a stable ID.
Example
automations/find-support-channel.automation.ts
Inputs
Output
Returns a normalizedSlackConversation with stable id and available name,
visibility, membership, topic, purpose, creation, creator, and member metadata.
Lookup compares names case-insensitively across every accessible public and
private channel. It fails if there is no match or if an exact name matches more
than one channel; use an ID to avoid ambiguity.