fix: wire up 'Send Vote Email' button to POST /admin/orchestrate/email

- Add triggerOrchestrate() to API client calling POST /admin/orchestrate/{step}
- Replace dead <button> in Dashboard with VoteEmailButton component:
  onClick calls triggerOrchestrate('email'), shows toast spinner + success/error

frontend/src/pages/Dashboard.tsx

@@ -1,6 +1,8 @@
 import { useQuery } from '@tanstack/react-query'
+import { useState } from 'react'
 import { Link } from 'react-router-dom'
-import { CookingPot, CalendarDays, ShoppingCart, ChevronRight, Sparkles } from 'lucide-react'
+import { CookingPot, CalendarDays, ShoppingCart, ChevronRight, Sparkles, Loader2 } from 'lucide-react'
+import toast from 'react-hot-toast'
 import { mealPlannerApi } from '../api'
 import type { MealPlan, MealPlanItem } from '../types'
 import { Badge } from '../components/ui/Badge'
@@ -129,6 +131,34 @@ function DashboardSkeleton() {
   )
 }
 
+function VoteEmailButton() {
+  const [sendingVoteEmail, setSendingVoteEmail] = useState(false)
+
+  async function handleSend() {
+    setSendingVoteEmail(true)
+    try {
+      const res = await mealPlannerApi.admin.triggerOrchestrate('email')
+      const status = res.data?.status || res.data?.message || 'sent'
+      toast.success(status)
+    } catch (err: any) {
+      toast.error(err?.response?.data?.detail || 'Failed to send vote emails')
+    } finally {
+      setSendingVoteEmail(false)
+    }
+  }
+
+  return (
+    <button
+      onClick={handleSend}
+      disabled={sendingVoteEmail}
+      className="inline-flex items-center gap-1 text-sm font-medium text-primary-600 hover:text-primary-700 transition-colors text-left disabled:opacity-50 disabled:cursor-not-allowed"
+    >
+      {sendingVoteEmail ? <Loader2 className="w-4 h-4 animate-spin" /> : <ChevronRight className="w-4 h-4" />}
+      {sendingVoteEmail ? 'Sending...' : 'Send Vote Email'}
+    </button>
+  )
+}
+
 export default function Dashboard() {
   const { data: mealPlan, isLoading } = useQuery<MealPlan | null>({
     queryKey: ['mealPlan'],
@@ -251,9 +281,7 @@ export default function Dashboard() {
                   >
                     Manage Pantry <ChevronRight className="w-4 h-4" />
                   </Link>
-                  <button className="inline-flex items-center gap-1 text-sm font-medium text-primary-600 hover:text-primary-700 transition-colors text-left">
-                    Send Vote Email <ChevronRight className="w-4 h-4" />
-                  </button>
+                  <VoteEmailButton />
                 </div>
               </div>
             </div>