feat: complete tRPC integration and fix platform UI issues

- Implement comprehensive tRPC setup with type-safe API
- Create tRPC routers for dashboard, admin, and auth endpoints
- Migrate frontend components to use tRPC client
- Fix platform dashboard Settings button functionality
- Add platform settings page with profile and security management
- Create OpenAI API mocking infrastructure for cost-safe testing
- Update tests to work with new tRPC architecture
- Sync database schema to fix AIBatchRequest table errors

app/platform/dashboard/page.tsx

@@ -7,9 +7,12 @@ import {
   Check,
   Copy,
   Database,
+  LogOut,
+  MoreVertical,
   Plus,
   Search,
   Settings,
+  User,
   Users,
 } from "lucide-react";
 import { useRouter } from "next/navigation";
@@ -26,6 +29,14 @@ import {
   DialogTitle,
   DialogTrigger,
 } from "@/components/ui/dialog";
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuLabel,
+  DropdownMenuSeparator,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import { ThemeToggle } from "@/components/ui/theme-toggle";
@@ -367,10 +378,45 @@ export default function PlatformDashboard() {
                   className="pl-10 w-64"
                 />
               </div>
-              <Button variant="outline" size="sm">
-                <Settings className="w-4 h-4 mr-2" />
-                Settings
-              </Button>
+              <DropdownMenu>
+                <DropdownMenuTrigger asChild>
+                  <Button variant="outline" size="sm">
+                    <MoreVertical className="w-4 h-4" />
+                  </Button>
+                </DropdownMenuTrigger>
+                <DropdownMenuContent align="end" className="w-56">
+                  <DropdownMenuLabel>
+                    <div className="flex flex-col space-y-1">
+                      <p className="text-sm font-medium">
+                        {session.user.name || session.user.email}
+                      </p>
+                      <p className="text-xs text-muted-foreground">
+                        {session.user.platformRole || "Platform User"}
+                      </p>
+                    </div>
+                  </DropdownMenuLabel>
+                  <DropdownMenuSeparator />
+                  <DropdownMenuItem
+                    onClick={() => router.push("/platform/settings")}
+                  >
+                    <User className="w-4 h-4 mr-2" />
+                    Account Settings
+                  </DropdownMenuItem>
+                  <DropdownMenuSeparator />
+                  <DropdownMenuItem
+                    onClick={async () => {
+                      await fetch("/api/platform/auth/logout", {
+                        method: "POST",
+                      });
+                      router.push("/platform/login");
+                    }}
+                    className="text-red-600"
+                  >
+                    <LogOut className="w-4 h-4 mr-2" />
+                    Sign Out
+                  </DropdownMenuItem>
+                </DropdownMenuContent>
+              </DropdownMenu>
             </div>
           </div>
         </div>