Fix upload timeout + apply Lumière to settings/auth pages

Nginx: add dedicated upload location with client_body_timeout 15m,
client_max_body_size 550m, and proxy_request_buffering off. Default
client_body_timeout of 60s was the actual culprit cutting slow uploads.
Node.js requestTimeout (build 228) remains as a backstop.

Lumière: pass isLumiere from UserPagesController (settings),
PasswordResetController (set-password), and UserActivateController
(first-time activation). auth.scss adds card styling for auth pages.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/web/modules/user-activate/app/src/UserActivateController.mjs

@@ -40,6 +40,7 @@ async function activateAccountPage(req, res, next) {
   const user = await UserGetter.promises.getUser(req.query.user_id, {
     email: 1,
     loginCount: 1,
+    'ace.overallTheme': 1,
   })
 
   if (!user) {
@@ -59,6 +60,7 @@ async function activateAccountPage(req, res, next) {
     title: 'activate_account',
     email: user.email,
     token: req.query.token,
+    isLumiere: (user?.ace?.overallTheme ?? '') === 'lumiere-',
   })
 }