fix(ui): admin settings loading-loop, real user name, expanded admin nav

SettingsFormCard
- Parent components pass `FIELDS.slice(...)` inline, so the prop reference
  changes on every render. The fetch callback's useCallback re-created
  itself, useEffect re-fired, and loading flicker meant the form never
  rendered. Capture fields in a ref so the callback is stable.

Sidebar
- Show real user name + avatar initial from session/profile, replacing
  the hardcoded "User Name" / "U" placeholder.
- Default the admin-section to expanded so its items are reachable on
  first page load (was collapsed behind a chevron).

Dashboard layout
- Pass {name, email} from the session/profile through to <Sidebar />.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/(dashboard)/layout.tsx

@@ -38,7 +38,14 @@ export default async function DashboardLayout({ children }: { children: React.Re
         <PermissionsProvider>
           <SocketProvider>
             <div className="flex h-screen overflow-hidden bg-background">
-              <Sidebar portRoles={portRoles} isSuperAdmin={profile?.isSuperAdmin ?? false} />
+              <Sidebar
+                portRoles={portRoles}
+                isSuperAdmin={profile?.isSuperAdmin ?? false}
+                user={{
+                  name: profile?.displayName ?? session.user.name ?? session.user.email,
+                  email: session.user.email,
+                }}
+              />
               <div className="flex-1 flex flex-col overflow-hidden min-w-0">
                 <Topbar ports={ports} />
                 <main className="flex-1 overflow-y-auto bg-background p-6">{children}</main>