Feature: Add password change functionality for admin and customers

- Add customer password change page at /account/change-password
- Add admin password change page at /admin/change-password
- Create AdminUser database table for storing admin credentials
- Admin login now checks database first, falls back to env vars
- Update admin auth to support bcrypt password hashing
- Add change password links to customer account and admin nav
- Fix customer login logs back link (was pointing to non-existent /admin)
- Add success/error message handling for password changes

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

src/app/admin/change-password/actions.ts

@@ -0,0 +1,49 @@
+'use server';
+
+import { redirect } from 'next/navigation';
+import { isAdminAuthenticated, getAdminUser, verifyPassword, hashPassword, createOrUpdateAdminUser } from '@/lib/adminAuth';
+
+export async function changeAdminPassword(formData: FormData) {
+  const isAuthenticated = await isAdminAuthenticated();
+  if (!isAuthenticated) redirect('/admin/login');
+
+  const currentPassword = String(formData.get('currentPassword') ?? '');
+  const newPassword = String(formData.get('newPassword') ?? '');
+  const confirmPassword = String(formData.get('confirmPassword') ?? '');
+
+  // Validate
+  if (!currentPassword || !newPassword || !confirmPassword) {
+    redirect('/admin/change-password?error=missing_fields');
+  }
+
+  if (newPassword.length < 8) {
+    redirect('/admin/change-password?error=password_too_short');
+  }
+
+  if (newPassword !== confirmPassword) {
+    redirect('/admin/change-password?error=passwords_dont_match');
+  }
+
+  // Get current admin user from database
+  const dbAdmin = await getAdminUser();
+
+  // Verify current password
+  let isValid = false;
+  if (dbAdmin) {
+    isValid = await verifyPassword(currentPassword, dbAdmin.passwordHash);
+  } else {
+    // Fall back to env vars if no database entry
+    isValid = currentPassword === process.env.ADMIN_PASSWORD;
+  }
+
+  if (!isValid) {
+    redirect('/admin/change-password?error=invalid_current');
+  }
+
+  // Update or create admin user with new password
+  const hashedPassword = await hashPassword(newPassword);
+  const username = dbAdmin?.username ?? process.env.ADMIN_USER ?? 'admin';
+  await createOrUpdateAdminUser(username, hashedPassword);
+
+  redirect('/admin/orders?success=password_changed');
+}

src/app/admin/change-password/page.tsx

@@ -0,0 +1,83 @@
+import Link from 'next/link';
+import { redirect } from 'next/navigation';
+import { isAdminAuthenticated } from '@/lib/adminAuth';
+import { changeAdminPassword } from './actions';
+
+const ERROR_MESSAGES: Record<string, string> = {
+  missing_fields: 'Please fill in all fields.',
+  password_too_short: 'Password must be at least 8 characters.',
+  passwords_dont_match: 'Passwords do not match.',
+  invalid_current: 'Current password is incorrect.',
+};
+
+export default async function ChangeAdminPasswordPage({ searchParams }: { searchParams: { error?: string } }) {
+  const isAuthenticated = await isAdminAuthenticated();
+  if (!isAuthenticated) redirect('/admin/login');
+
+  const error = searchParams.error ? ERROR_MESSAGES[searchParams.error] : null;
+
+  return (
+    <div className="mx-auto max-w-2xl px-6 py-12">
+      <Link href="/admin/orders" className="tag-label text-muted hover:text-clay">
+        ← Back to orders
+      </Link>
+
+      <h1 className="mt-6 font-display text-3xl">Change admin password</h1>
+      <p className="mt-2 text-muted">Update your admin account password</p>
+
+      {error && (
+        <p className="mt-6 border border-splash-pink/40 bg-splash-pink/10 px-4 py-3 text-sm text-splash-pink">
+          {error}
+        </p>
+      )}
+
+      <form action={changeAdminPassword} className="mt-8 max-w-md space-y-6">
+        <div>
+          <label htmlFor="current" className="tag-label mb-2 block">
+            Current password
+          </label>
+          <input
+            id="current"
+            name="currentPassword"
+            type="password"
+            required
+            className="w-full border border-line bg-paper px-3 py-2 text-sm"
+          />
+        </div>
+
+        <div>
+          <label htmlFor="new" className="tag-label mb-2 block">
+            New password
+          </label>
+          <input
+            id="new"
+            name="newPassword"
+            type="password"
+            required
+            minLength={8}
+            className="w-full border border-line bg-paper px-3 py-2 text-sm"
+          />
+          <p className="mt-1 text-xs text-muted">At least 8 characters</p>
+        </div>
+
+        <div>
+          <label htmlFor="confirm" className="tag-label mb-2 block">
+            Confirm new password
+          </label>
+          <input
+            id="confirm"
+            name="confirmPassword"
+            type="password"
+            required
+            minLength={8}
+            className="w-full border border-line bg-paper px-3 py-2 text-sm"
+          />
+        </div>
+
+        <button type="submit" className="bg-clay px-6 py-2 text-sm font-medium text-paper hover:bg-clay-dark">
+          Update password
+        </button>
+      </form>
+    </div>
+  );
+}

src/app/admin/customer-login-logs/page.tsx

@@ -31,8 +31,8 @@ export default async function CustomerLoginLogsPage() {
       <AdminNav />
       <div className="flex flex-wrap items-baseline justify-between gap-3">
         <h1 className="font-display text-3xl">Customer Login Activity</h1>
-        <Link href="/admin" className="text-sm text-clay hover:text-clay-dark">
-          Back to admin
+        <Link href="/admin/orders" className="text-sm text-clay hover:text-clay-dark">
+          Back to orders
         </Link>
       </div>
 

src/app/admin/login/actions.ts

@@ -5,6 +5,7 @@ import { redirect } from 'next/navigation';
 import { prisma } from '@/lib/prisma';
 import { createAdminSession, clearAdminSession } from '@/lib/adminAuth';
 import { checkRateLimit, getClientIp } from '@/lib/rateLimit';
+import { getAdminUser, verifyPassword } from '@/lib/adminAuth';
 
 function safeNext(next: FormDataEntryValue | null) {
   const path = String(next ?? '');
@@ -28,7 +29,20 @@ export async function loginAdmin(formData: FormData) {
     redirect(`/admin/login?error=rate_limited&next=${encodeURIComponent(next)}`);
   }
 
-  if (username !== process.env.ADMIN_USER || password !== process.env.ADMIN_PASSWORD) {
+  let isValid = false;
+
+  // Check database first (if using database-stored credentials)
+  const dbAdmin = await getAdminUser();
+  if (dbAdmin && username === dbAdmin.username) {
+    isValid = await verifyPassword(password, dbAdmin.passwordHash);
+  }
+
+  // Fall back to env vars if no database entry or match
+  if (!isValid && username === process.env.ADMIN_USER && password === process.env.ADMIN_PASSWORD) {
+    isValid = true;
+  }
+
+  if (!isValid) {
     // Log failed attempt (wrong credentials)
     await prisma.adminLoginLog.create({
       data: { success: false, ipAddress: ip, userAgent },

src/app/admin/orders/page.tsx

@@ -22,9 +22,15 @@ const STATUS_STYLES: Record<string, string> = {
   DELIVERED: 'bg-green-500/10 text-green-600',
 };
 
-export default async function OrdersPage({ searchParams }: { searchParams: { archived?: string; personalised?: string } }) {
+const SUCCESS_MESSAGES: Record<string, string> = {
+  password_changed: 'Password updated successfully.',
+};
+
+export default async function OrdersPage({ searchParams }: { searchParams: { archived?: string; personalised?: string; success?: string } }) {
   await autoArchiveOldOrders();
 
+  const success = searchParams.success ? SUCCESS_MESSAGES[searchParams.success] : null;
+
   const showArchived = searchParams.archived === '1';
   const showOnlyPersonalised = searchParams.personalised === '1';
 
@@ -63,6 +69,11 @@ export default async function OrdersPage({ searchParams }: { searchParams: { arc
   return (
     <div className="mx-auto max-w-4xl px-6 py-12">
       <AdminNav />
+      {success && (
+        <div className="mb-6 border border-green-500/40 bg-green-500/10 px-4 py-3 text-sm text-green-700">
+          ✓ {success}
+        </div>
+      )}
       <div className="flex items-baseline justify-between">
         <h1 className="font-display text-3xl">{showArchived ? 'Archived orders' : 'Orders'}</h1>
         <Link href={showArchived ? '/admin/orders' : '/admin/orders?archived=1'} className="tag-label hover:text-ink">