Standardize page width, card layouts; mark SSO users external and read-only

- All pages now wrap their content in <div class="container mt-4">,
  matching sso-manager-node's width instead of rendering full-bleed inside
  the fluid shell.
- Users and Permissions pages converted from bare <table>s to the same
  card-grid convention already used on the Groups page.
- Users backed by SSO/OIDC login (backing === 'oidc', set by the redis
  user model's JIT-provisioning path) are now marked "External (SSO)" and
  their password-change control is hidden; PUT /password/:username also
  rejects with 403 server-side for such users. Deletion stays allowed.
  Redis-backend only -- LDAP/PAM deployments have no per-record marker for
  this today.
- app-base.js (byte-identical across the 3 apps): added
  app.util.revealItem(), wired into the Users/Permissions create flows.
- Bumped @simpleworkjs/frontend to ^0.2.7.

nodejs/public/css/styles.css

@@ -7,6 +7,12 @@ body {
 	display: flex;
 	flex-direction: column;
 	min-height: 100vh;
+	/* Height of the fixed navbar (plus the update banner, while shown --
+	   see top.ejs's showUpdateBanner/dismissUpdateBanner). Lets an in-page
+	   sticky element offset itself below both fixed elements via
+	   `top: var(--sw-content-offset)` instead of colliding with them at the
+	   viewport's true top:0. */
+	--sw-content-offset: 4.5rem;
 }
 
 #spa-shell {