chore(deps): drop next-themes; remove ThemeProvider + theme toggle UI

src/app/globals.css

@@ -218,35 +218,6 @@
     --info: 194 25% 44%;
   }
 
-  .dark {
-    --background: 220 15% 8%;
-    --foreground: 0 0% 98%;
-
-    --card: 220 15% 10%;
-    --card-foreground: 0 0% 98%;
-
-    --popover: 220 15% 10%;
-    --popover-foreground: 0 0% 98%;
-
-    --primary: 354 90% 50%;
-    --primary-foreground: 0 0% 100%;
-
-    --secondary: 220 15% 18%;
-    --secondary-foreground: 0 0% 98%;
-
-    --muted: 220 15% 18%;
-    --muted-foreground: 0 0% 64%;
-
-    --accent: 194 20% 18%;
-    --accent-foreground: 0 0% 98%;
-
-    --destructive: 0 84% 55%;
-    --destructive-foreground: 0 0% 100%;
-
-    --border: 220 15% 22%;
-    --input: 220 15% 22%;
-    --ring: 220 10% 50%;
-  }
 }
 
 @layer base {
@@ -345,13 +316,6 @@ div[class*="recharts-tooltip"] {
   opacity: 1 !important;
 }
 
-.dark div[class*="tremor"][class*="tooltip"],
-.dark .recharts-tooltip-wrapper .recharts-default-tooltip,
-.dark div[class*="recharts-tooltip"] {
-  background-color: hsl(var(--card)) !important;
-  border-color: hsl(var(--border)) !important;
-}
-
 /* Tremor/Recharts tooltip color indicator icons — fix rendering */
 .recharts-tooltip-wrapper svg.recharts-surface {
   display: inline-block !important;

src/app/providers.tsx

@@ -2,7 +2,6 @@
 
 import { useState } from 'react'
 import { SessionProvider } from 'next-auth/react'
-import { ThemeProvider } from 'next-themes'
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
 import { httpBatchLink } from '@trpc/client'
 import superjson from 'superjson'
@@ -78,12 +77,10 @@ export function Providers({ children }: { children: React.ReactNode }) {
   )
 
   return (
-    <ThemeProvider attribute="class" defaultTheme="light" enableSystem={false}>
-      <SessionProvider>
-        <trpc.Provider client={trpcClient} queryClient={queryClient}>
-          <QueryClientProvider client={queryClient}>{children}</QueryClientProvider>
-        </trpc.Provider>
-      </SessionProvider>
-    </ThemeProvider>
+    <SessionProvider>
+      <trpc.Provider client={trpcClient} queryClient={queryClient}>
+        <QueryClientProvider client={queryClient}>{children}</QueryClientProvider>
+      </trpc.Provider>
+    </SessionProvider>
   )
 }

src/components/layouts/role-nav.tsx

@@ -19,11 +19,10 @@ import {
 import type { Route } from 'next'
 import type { LucideIcon } from 'lucide-react'
 import {
-  LogOut, Menu, Moon, Settings, Sun, User, X,
+  LogOut, Menu, Settings, User, X,
   ArrowRightLeft,
   ExternalLink as ExternalLinkIcon, HelpCircle, Mail,
 } from 'lucide-react'
-import { useTheme } from 'next-themes'
 import { Logo } from '@/components/shared/logo'
 import { NotificationBell } from '@/components/shared/notification-bell'
 import { useRoleSwitcher, RoleSwitcherPill } from './role-switcher'
@@ -69,9 +68,6 @@ export function RoleNav({ navigation, roleName, user, basePath, statusBadge, edi
   })
   const endImpersonation = trpc.user.endImpersonation.useMutation()
   const logNavClick = trpc.learningResource.logNavClick.useMutation()
-  const { theme, setTheme } = useTheme()
-  const [mounted, setMounted] = useState(false)
-  useEffect(() => setMounted(true), [])
 
   const handleSignOut = async () => {
     if (isImpersonating) {
@@ -172,20 +168,6 @@ export function RoleNav({ navigation, roleName, user, basePath, statusBadge, edi
                 </DropdownMenuContent>
               </DropdownMenu>
             )}
-            {mounted && (
-              <Button
-                variant="ghost"
-                size="icon"
-                onClick={() => setTheme(theme === 'dark' ? 'light' : 'dark')}
-                aria-label="Toggle theme"
-              >
-                {theme === 'dark' ? (
-                  <Sun className="h-5 w-5" />
-                ) : (
-                  <Moon className="h-5 w-5" />
-                )}
-              </Button>
-            )}
             <RoleSwitcherPill currentBasePath={basePath} />
             <NotificationBell />
             <DropdownMenu>