fix: TOTP login flow loses remember_me — sessions expire after 1 hour

The TOTP verification endpoint always created refresh tokens with
remember_me=false and 1-hour expiry, regardless of what the user
selected at login.

Fix:
- Frontend now sends remember_me in the TOTP verify request body
- Backend reads remember_me and uses it for token expiry (30 days)
  and cookie maxAge

Users with 2FA who checked "remember me" will now stay logged in
for 30 days instead of being kicked out after 1 hour.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/admin/context/AuthContext.tsx

@@ -198,7 +198,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
         credentials: 'include',
-        body: JSON.stringify({ login_token: loginToken, totp_code: code }),
+        body: JSON.stringify({ login_token: loginToken, totp_code: code, remember_me: remember }),
       })
       const data = await response.json()
       if (data.success) {