Teams, passkeys and a terminal that keeps its session

Added

• Teams with owners and members. A ShellBase account is no longer one person. Teams carry an owner, members and a plan; new teams start on Free with member and server limits that the plan defines.
• Invitations and notifications. Invitations arrive in the app rather than by side channel, and the same surface reports when a team runs into its member or server limit.
• Passkey sign-in. Registration and login now work with WebAuthn — fingerprint, face or device PIN instead of a password.
• SSO per team. A team can bind sign-in to its own domain, validated against the domain it claims.
• Error reporting. The dashboard reports its own failures through Artim Stacktrace instead of losing them in the browser console.

Improved

• Terminal sessions survive navigation. Session handling was rewritten so switching tabs in settings no longer tears down the shell.
• Policy changes carry their author. Every policy update now records which address made it and when — the beginning of an audit trail.

Fixed

• SSH key loading failed for DSS keys and reported nothing useful when a server connection test went wrong. Both now say what happened.
• The WebAuthn relying-party id came from two places and disagreed with itself; it now comes from the settings alone.
• The dashboard opened in dark mode regardless of preference.