fix: replace invalid TanStack Router search casts with typed defaults

Newer TanStack Router enforces strict types on search params — 'search: {} as Record<string, unknown>' no longer satisfies routes with validateSearch. Replace all occurrences with the correct search shape for each destination route (pagination defaults for list routes, tab/field defaults for detail routes).

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

packages/admin/src/routes/login.tsx

@@ -7,7 +7,7 @@ export const Route = createFileRoute('/login')({
   beforeLoad: () => {
     const { token } = useAuthStore.getState()
     if (token) {
-      throw redirect({ to: '/accounts', search: {} as Record<string, unknown> })
+      throw redirect({ to: '/accounts', search: { page: 1, limit: 25, q: undefined, sort: undefined, order: 'asc' as const } })
     }
   },
   component: LoginPage,
@@ -30,7 +30,7 @@ function LoginPage() {
       const res = await login(email, password)
       setAuth(res.token, res.user)
       await router.invalidate()
-      await router.navigate({ to: '/accounts', search: {} as Record<string, unknown>, replace: true })
+      await router.navigate({ to: '/accounts', search: { page: 1, limit: 25, q: undefined, sort: undefined, order: 'asc' as const }, replace: true })
     } catch (err) {
       setError(err instanceof Error ? err.message : 'Login failed')
     } finally {