cli: resolve the recap repo scope and display name in one pass

Review finding on the cell path: newRecapClient resolved the origin remote (plus the control-plane mirror lookup) via currentRepoID, then runRecap resolved the same remote again via currentRepoSlug for the scope-line display name — two git resolutions per recap.

currentRepoID becomes currentRepoRef and returns (repoID, repoSlug) from the single resolution it already does; newRecapClient threads both through, and the data-API path returns its slug as both scope and name. runRecap no longer re-resolves. An un-mirrored repo yields empty scope AND name, preserving the unscoped-recap-isn't-mislabelled rule.