Channel is the transport the request arrived on — discord, slack, teams or telegram — and half of what approval names. The cap of three unapproved requests applies per (org, channel); while it is full no further code is minted until one is approved or expires.
Code is the CAPABILITY that authorises the approval: eight characters from a 32-symbol uppercase alphabet (A-Z0-9 minus the confusables 0, O, 1 and I), minted with crypto/rand and also sent to the requester in chat. An org admin passes it with the channel to POST /v1/channels/pairing/approve, which CONSUMES it — the request row is deleted, so a code approves once — and which takes org admin as well as the code. It lives ONE HOUR from CreatedAt; expired requests are not listed here, and approving one is a 404. It is shown on this admin surface and NEVER logged.
LastSeen is Unix SECONDS of the MOST RECENT message from this sender while the request has been pending. It moves as they keep writing, which is how an admin tells a live request from an abandoned one — but it does not extend the hour and does not re-send the code, since one request sends exactly one chat reply.
Sender is the transport-native user id waiting for access — the same identity inbox messages carry. Approving mints a DM allow entry for exactly this value and nothing wider: pairing never grants group access.
