feat(hub): default email opt-outs and match Register to Login styling

- Invitation-by-email and recovery-key-by-email boxes now start unchecked;
  mailing a code/key is opt-in. The invite choice still remembers itself
  per account once set.
- Align the two invite-email checkboxes with their label (center, not
  flex-start).
- Register (and its verify/recovery/done steps) now sits on the same dark
  gradient backdrop and frosted card as Login, via a shared AuthShell.
- Make the gradient's top-left corner very slightly less bright
  (#86a3c4 -> #809cbc), on both auth pages.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/packages/meshbay-hub/tests/test_invite_email_choice.py b/packages/meshbay-hub/tests/test_invite_email_choice.py
index e04c31f..de9410d 100644
--- a/packages/meshbay-hub/tests/test_invite_email_choice.py
+++ b/packages/meshbay-hub/tests/test_invite_email_choice.py
@@ -3,8 +3,9 @@ Whether the hub mails an invitation is the inviter's choice, and it is remembere
 
 Mailing it hands the hub the code — `invite-notify` writes it into the message —
 which is exactly what §3.4 says the code is for not doing. So the Members tab
-offers it as a box, checked by default, and an unchecked box must mean the hub
-is never asked. The choice lives in an account preference; a key the hub does
+offers it as a box, unchecked by default (mailing the code is opt-in), and an
+unchecked box must mean the hub is never asked. The choice lives in an account
+preference, remembered once set; a key the hub does
 not list is refused, and the box would snap back on every click with nothing on
 screen to say why.
 """