feat(auth): sidebar shows current user + logout button

src/components/Sidebar.tsx

@@ -7,6 +7,7 @@ import {
   Inbox as InboxIcon,
   Layers,
   LayoutDashboard,
+  LogOut,
   Receipt,
   Stethoscope,
   Upload as UploadIcon,
@@ -14,6 +15,7 @@ import {
 } from "lucide-react";
 import { cn } from "@/lib/utils";
 import { useReconciliation } from "@/hooks/useReconciliation";
+import { useAuth } from "@/auth/useAuth";
 
 const nav = [
   { to: "/", label: "Dashboard", icon: LayoutDashboard, end: true },
@@ -188,25 +190,70 @@ export function Sidebar() {
       </nav>
 
       {/* Operator card — always at the bottom. Ringed, mono id, the
-          account role under the name. */}
+          account role under the name. The avatar initial + username +
+          role all come from `useAuth()` now (replaced the hardcoded
+          "Jordan K. / Administrator"); the Sign out button next to it
+          hits `authApi.logout` and drops the operator back at /login. */}
       <div className="px-3 py-4 border-t border-sidebar-border/80">
-        <div className="flex items-center gap-3 rounded-md p-2 hover:bg-muted/40 cursor-default">
-          <div className="relative h-8 w-8 rounded-full bg-accent/20 ring-1 ring-inset ring-accent/40 flex items-center justify-center text-[10.5px] font-semibold text-accent mono">
-            JK
-            <span className="absolute -bottom-0.5 -right-0.5 h-2.5 w-2.5 rounded-full bg-[hsl(var(--success))] ring-2 ring-sidebar" />
-          </div>
-          <div className="leading-tight min-w-0">
-            <div className="text-[13px] font-medium truncate">Jordan K.</div>
-            <div className="mono text-[10px] text-muted-foreground tracking-wider uppercase">
-              Administrator
-            </div>
-          </div>
-        </div>
+        <CurrentUserCard />
       </div>
     </aside>
   );
 }
 
+/**
+ * Bottom-of-sidebar identity card. Driven by `useAuth()` so the
+ * username + role update whenever the operator's session changes
+ * (e.g. an admin re-grants a role via the admin pages, or the
+ * session expires and a fresh login lands them back with a
+ * different username).
+ */
+function CurrentUserCard() {
+  const { user, logout } = useAuth();
+  if (!user) {
+    // Shouldn't happen — the route guard ensures the sidebar only
+    // mounts after auth is established. Render a harmless placeholder
+    // so the layout doesn't reflow if the context ever lags.
+    return (
+      <div
+        className="flex items-center gap-3 rounded-md p-2 text-[12px] text-muted-foreground"
+        aria-hidden
+      >
+        <div className="h-8 w-8 rounded-full bg-muted/40" />
+        <div className="leading-tight">Signed out</div>
+      </div>
+    );
+  }
+  // Use the first letter of the username for the avatar monogram;
+  // fall back to "?" if the username is somehow empty.
+  const initial = user.username?.[0]?.toUpperCase() ?? "?";
+  return (
+    <div className="flex items-center gap-3 rounded-md p-2 hover:bg-muted/40 group">
+      <div className="relative h-8 w-8 rounded-full bg-accent/20 ring-1 ring-inset ring-accent/40 flex items-center justify-center text-[10.5px] font-semibold text-accent mono shrink-0">
+        {initial}
+        <span className="absolute -bottom-0.5 -right-0.5 h-2.5 w-2.5 rounded-full bg-[hsl(var(--success))] ring-2 ring-sidebar" />
+      </div>
+      <div className="leading-tight min-w-0 flex-1">
+        <div className="text-[13px] font-medium truncate">{user.username}</div>
+        <div className="mono text-[10px] text-muted-foreground tracking-wider uppercase">
+          {user.role}
+        </div>
+      </div>
+      <button
+        type="button"
+        onClick={() => {
+          void logout();
+        }}
+        aria-label="Sign out"
+        title="Sign out"
+        className="shrink-0 inline-flex items-center justify-center h-7 w-7 rounded-md text-muted-foreground hover:text-foreground hover:bg-muted/60 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring opacity-60 group-hover:opacity-100"
+      >
+        <LogOut className="h-3.5 w-3.5" strokeWidth={1.5} />
+      </button>
+    </div>
+  );
+}
+
 function SectionLabel({ children }: { children: React.ReactNode }) {
   return (
     <div className="px-3 mb-1.5 eyebrow text-muted-foreground/60">