feat(client): logged-in user card in sidebar (always visible)

The earlier UserPill landed in the TitleBar tab strip, but the main
desktop layout (HeicodeTasksHome shell) renders its own chrome without
that strip — so the user info ended up invisible despite mcpAuth
having the right data after a2deeb6. Pull the same identity (avatar
gradient + name + email + role badge) straight into the bottom of
Sidebar.tsx, right above the logout/settings rows, so it's visible
on every screen regardless of which top bar is mounted.

Two layouts:
- expanded: 36px gradient avatar + name + email + admin/root badge
- collapsed: 36px avatar circle only, title tooltip carries the email

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

cc-haha/desktop/src/components/layout/Sidebar.tsx

@@ -36,6 +36,12 @@ export function Sidebar() {
   const closeTab = useTabStore((s) => s.closeTab)
   const disconnectSession = useChatStore((s) => s.disconnectSession)
   const logout = useHeicodeAuthStore((s) => s.logout)
+  // Logged-in user identity, surfaced as a card right above logout/settings so
+  // the user can always SEE who they're signed in as without clicking anywhere.
+  // Populated by /api/heicode-auth/status from the active provider's mcpAuth
+  // record (credentials login → set in handleLoginWithCredentials; OAuth login
+  // → set from query params by handleOAuthCallback after backend a2deeb6).
+  const authUser = useHeicodeAuthStore((s) => s.status?.user ?? null)
   const [searchQuery, setSearchQuery] = useState('')
   const [contextMenu, setContextMenu] = useState<{ id: string; x: number; y: number } | null>(null)
   const [pendingDeleteSessionId, setPendingDeleteSessionId] = useState<string | null>(null)
@@ -372,7 +378,8 @@ export function Sidebar() {
         <div className="flex-1" aria-hidden="true" />
       )}
 
-      <div className={`border-t border-[var(--color-border)] p-3 ${sidebarOpen ? '' : 'flex justify-center'}`}>
+      <div className={`border-t border-[var(--color-border)] p-3 ${sidebarOpen ? '' : 'flex flex-col items-center'}`}>
+        {authUser ? <SidebarUserCard user={authUser} collapsed={!sidebarOpen} /> : null}
         <div className={`mb-1 ${sidebarOpen ? '' : 'mb-2'}`}>
           <NavItem
             active={false}
@@ -508,6 +515,78 @@ function NavItem({
   )
 }
 
+// Logged-in user card in the bottom sidebar — gradient-filled avatar +
+// name + email + role badge. Always visible so the user can see who they
+// are signed in as without clicking anywhere. Two layouts: expanded (full
+// pill) and collapsed (small avatar circle with title tooltip).
+function SidebarUserCard({
+  user,
+  collapsed,
+}: {
+  user: {
+    email?: string
+    displayName?: string
+    role?: string
+    userId?: string
+  }
+  collapsed: boolean
+}) {
+  const name = user.displayName?.trim() || user.email?.trim() || 'You'
+  const initial = (name.slice(0, 1) || '?').toUpperCase()
+  const role = user.role?.trim().toLowerCase()
+  const roleBadge = role && role !== 'user' && role !== '1' ? role : null
+
+  if (collapsed) {
+    return (
+      <div
+        className="mb-2 flex h-9 w-9 items-center justify-center rounded-full text-[12px] font-bold text-white"
+        style={{ backgroundImage: 'var(--gradient-brand-wordmark)' }}
+        title={user.email || name}
+      >
+        {initial}
+      </div>
+    )
+  }
+
+  return (
+    <div
+      className="mb-2 flex items-center gap-2.5 rounded-[12px] border px-2.5 py-2"
+      style={{
+        borderColor: 'rgba(123,107,227,0.22)',
+        backgroundColor: 'rgba(123,107,227,0.06)',
+      }}
+    >
+      <span
+        className="flex h-8 w-8 flex-shrink-0 items-center justify-center rounded-full text-xs font-bold text-white"
+        style={{ backgroundImage: 'var(--gradient-brand-wordmark)' }}
+      >
+        {initial}
+      </span>
+      <div className="min-w-0 flex-1 leading-tight">
+        <div className="truncate text-[12px] font-semibold text-[var(--color-text-primary)]">
+          {name}
+        </div>
+        {user.email && (
+          <div className="truncate text-[10px] text-[var(--color-text-tertiary)]">
+            {user.email}
+          </div>
+        )}
+      </div>
+      {roleBadge && (
+        <span
+          className="flex-shrink-0 rounded-full px-1.5 py-0.5 text-[9px] font-semibold uppercase tracking-wider"
+          style={{
+            backgroundColor: 'rgba(123,107,227,0.14)',
+            color: 'var(--color-primary)',
+          }}
+        >
+          {roleBadge}
+        </span>
+      )}
+    </div>
+  )
+}
+
 function formatRelativeTime(dateStr: string): string {
   const diff = Date.now() - new Date(dateStr).getTime()
   const min = Math.floor(diff / 60000)