fix(sso): preserve admin-assigned roles across SSO sign-in (#1862)

* fix(sso): preserve admin-assigned roles across SSO sign-in

An SSO/OIDC/LDAP user's role was overwritten by the IdP-derived role on
every sign-in, so a role an admin assigned in Settings > Users reverted to
the provider default on the next login. Gate role re-sync behind an opt-in
sso_role_sync setting (default off), so manual role edits persist unless the
operator explicitly enables IdP-authoritative sync. Email continues to sync
unconditionally.

Adds human-session-only GET/PUT /api/sso/config/role-sync endpoints with a
hub-side API-token rejection in the remote proxy, a frontend toggle, a
regenerated SSO settings screenshot, and matching docs.

Closes #1851

* fix(sso): satisfy CodeQL on role-sync log and test token hashing

Route three inline API-token creation blocks through the shared
createTestApiToken helper so the sha256 hashing lives in one place, and
log the role-sync toggle as a word instead of a raw boolean. No behavior
change; resolves the CodeQL js/insecure-hashing and log-injection alerts.

* fix(sso): harden role-sync gate, name the toggle, fix screenshot

Addresses pre-merge review findings on the SSO role-sync feature:
- Make the hub-side SSO config authz guard case-insensitive to match
  Express routing semantics, closing a case-variant API-token bypass.
- Give the IdP role-sync switch an accessible name.
- Capture the SSO settings screenshot at desktop size with the scroll
  area expanded so the role-sync control is fully visible.

docs/tutorials/set-up-sso.mdx

@@ -91,7 +91,7 @@ Check from two places, since either alone only shows one side of provisioning.
   <img src="/images/tutorials/set-up-sso/users-list-provisioned.png" alt="The Users table under Settings, Access, Users, with a row for the newly auto-provisioned SSO user showing role Viewer and today's date under Created." />
 </Frame>
 
-On every later sign-in, this same account is reused. Its email and role are re-synced from the identity provider each time, so promoting or removing someone from your directory takes effect on their next login.
+On every later sign-in, this same account is reused. Its email is re-synced from the identity provider. Its role stays whatever is set on the account, so a manual role edit in **Settings · Users** persists. To have the identity provider reapply the role on each login instead, enable **IdP role synchronization** in **Settings · SSO**; then promoting or removing someone from your directory takes effect on their next login.
 
 ## If something goes wrong