fix: remove Manus OAuth button and unused imports from Login page

- Hide "Sign in with Manus Account" button and divider (not used in production)
- Remove unused Separator and getLoginUrl imports

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

client/src/pages/Login.tsx

@@ -2,7 +2,6 @@ import { useState } from "react";
 import { useLocation } from "wouter";
 import { trpc } from "@/lib/trpc";
 import { useAuth } from "@/_core/hooks/useAuth";
-import { getLoginUrl } from "@/const";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
@@ -14,7 +13,6 @@ import {
   CardHeader,
   CardTitle,
 } from "@/components/ui/card";
-import { Separator } from "@/components/ui/separator";
 import {
   Bot,
   Eye,
@@ -232,41 +230,6 @@ export default function Login() {
               </Button>
             </form>
 
-            {/* Divider */}
-            <div className="relative my-6">
-              <Separator style={{ background: "#e7e0d5" }} />
-              <span
-                className="absolute left-1/2 top-1/2 -translate-x-1/2 -translate-y-1/2 px-3 text-xs"
-                style={{
-                  background: "#fff",
-                  color: "#a8a29e",
-                  fontFamily: "'Source Sans 3', sans-serif",
-                }}
-              >
-                or continue with
-              </span>
-            </div>
-
-            {/* OAuth login */}
-            <Button
-              variant="outline"
-              className="w-full h-11 text-sm font-medium"
-              style={{
-                borderColor: "#e7e0d5",
-                color: "#57534e",
-                fontFamily: "'Source Sans 3', sans-serif",
-              }}
-              onClick={() => {
-                window.location.href = getLoginUrl("/dashboard");
-              }}
-              disabled={isLoading}
-            >
-              <svg className="w-4 h-4 mr-2" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2z" fill="#14532D" opacity="0.2"/>
-                <path d="M12 6a3 3 0 100 6 3 3 0 000-6zm0 8c-3.31 0-6 1.34-6 3v1h12v-1c0-1.66-2.69-3-6-3z" fill="#14532D"/>
-              </svg>
-              Sign in with Manus Account
-            </Button>
           </CardContent>
 
           <CardFooter className="justify-center pb-6">