Feature: Add customer search and selection to email page

- Create CustomerSelector component for searching and selecting customers
- Search by name or email with real-time filtering
- Select individual customers or select all with one click
- Shows count of selected customers
- Shows subscribed customer count in search results
- Updated email form to use selected customers
- Falls back to all subscribed if no customers selected
- Displays preview of recipient count before sending

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/app/admin/customers/actions.ts

@@ -31,7 +31,19 @@ export async function sendBulkEmail(formData: FormData) {
         }
       : null;
 
-  const recipients = await prisma.mailingListEntry.findMany({ where: { subscribed: true } });
+  // Get selected customer IDs from form
+  const selectedIds = formData.getAll('selectedCustomers') as string[];
+
+  let recipients;
+  if (selectedIds.length > 0) {
+    // Send to selected customers only
+    recipients = await prisma.mailingListEntry.findMany({
+      where: { id: { in: selectedIds } },
+    });
+  } else {
+    // Fall back to all subscribed if no selection made
+    recipients = await prisma.mailingListEntry.findMany({ where: { subscribed: true } });
+  }
 
   let sent = 0;
   let failed = 0;

src/app/admin/customers/page.tsx

@@ -1,5 +1,6 @@
 import { prisma } from '@/lib/prisma';
 import AdminNav from '@/components/AdminNav';
+import CustomerSelector from '@/components/CustomerSelector';
 import { updateSubscribed, sendBulkEmail } from './actions';
 
 const SOURCE_LABELS: Record<string, string> = {
@@ -75,6 +76,8 @@ export default async function CustomersPage({
 
       <h2 className="tag-label mt-10 mb-3 text-ink">Send an email</h2>
       <form action={sendBulkEmail} className="space-y-6">
+        <CustomerSelector entries={entries} sourceLabels={SOURCE_LABELS} />
+
         <div>
           <label htmlFor="subject" className="tag-label mb-2 block">
             Subject
@@ -107,7 +110,7 @@ export default async function CustomersPage({
           <input id="attachment" name="attachment" type="file" className="w-full text-sm" />
         </div>
         <button type="submit" className="bg-clay px-6 py-3 text-sm font-medium text-paper hover:bg-clay-dark">
-          Send to {subscribedCount} subscribed recipient{subscribedCount === 1 ? '' : 's'}
+          Send email
         </button>
       </form>
     </div>