Bare issue numbers: resolve the team via active profile, then favorited teams #59

Every issue-identifier argument needs the full team-prefixed form (CRY-1234) - Linear's own issue(id: $id) API field resolves either a UUID or that full identifier, never a bare number alone. lc issue develop 1234 should work like lc issue develop CRY-1234, inferring the CRY- prefix.

Resolution order, never a hard error: active profile's team (#56) -> favorited team(s) (depends on the favorites feature - see below) -> prompt across every team the user belongs to (WhatFor.ask_for_team/0's existing full-list fallback).

One shared LinearCli.CLI.IssueHelpers.expand_issue_id/1, reused at both real call sites: gimme_da_issue!/2 (covers issue develop/pr/take for free) and issue_list/issue_update, which call Linear.issues/1 directly.

Full design in documents/phase-11-plan.adoc. Depends on the favorited-teams/projects feature landing first.