c6918cbeea
JWTs were previously fully stateless -- the token alone was the credential until its own expiry, with no way to list or kill a session server-side. Add a UserSession table alongside every JWT issued (AppSessionIssuer), embed its id as a "sid" claim, and check that claim against the DB on every "local" scheme request (Program.cs OnTokenValidated) so a session can actually be revoked before its JWT naturally expires. New /api/auth/sessions endpoints (list, revoke one, revoke-others) plus a Sessions card on the profile page. Fails closed on a missing "sid" claim: every JWT issued going forward has one, so a token without it is either pre-deploy (forces one re-login for already-signed-in users at deploy time, same additive-forward cost the 2FA/trusted-device work on this branch already paid) or forged.