New Account Screen Redesign

Change New account screen: Initial view: - Provider dropdown, Authentication dropdown - one row - Node dropdown - Advanced collapsible with Name, Owner, Description, Auto-assign. If NodeLink shared is on, move Node to Advanced too - Button \[Authenticate\] with copy link link - same as \[Click to authorize\] - Remove the link text and status and Sign in - Authorization code box \[Confirm\] button. That turns into Close, but once it gets green it autocloses - Remove Sealed to the nodes public key Show screenshot in task Artifacts before building 

New account redesigned per the approved mockup. Sign-in is slimmed on every screen: Authenticate, Copy link, Confirm→Close, auto-close. Node folds into Advanced when it's on the accounts NodeLink (new NodeOut.accounts_nodelink). Quick gate and 983 tests green, visual check done at 1280px and 448px. PR #6473 is queued. Draft follow-up: 8534. Memory: none applied.