Add Portfolio collection with 7 fields

Create Portfolio collection for managing website portfolio items.
Includes title, slug, url, image, description, websiteType, and
tags fields. Configured access control for authenticated create/
update/delete operations with public read access.

apps/backend/src/collections/Portfolio/index.ts

@@ -0,0 +1,75 @@
+import type { CollectionConfig } from 'payload'
+
+import { authenticated } from '../../access/authenticated'
+import { anyone } from '../../access/anyone'
+import { slugField } from '@/fields/slug'
+
+export const Portfolio: CollectionConfig = {
+  slug: 'portfolio',
+  access: {
+    create: authenticated,
+    read: anyone,
+    update: authenticated,
+    delete: authenticated,
+  },
+  admin: {
+    useAsTitle: 'title',
+    defaultColumns: ['title', 'websiteType', 'updatedAt'],
+  },
+  fields: [
+    {
+      name: 'title',
+      type: 'text',
+      required: true,
+    },
+    {
+      name: 'url',
+      type: 'text',
+      admin: {
+        description: 'Website URL (e.g., https://example.com)',
+      },
+    },
+    {
+      name: 'image',
+      type: 'upload',
+      relationTo: 'media',
+      required: true,
+      admin: {
+        description: 'Preview image stored in R2',
+      },
+    },
+    {
+      name: 'description',
+      type: 'textarea',
+    },
+    {
+      name: 'websiteType',
+      type: 'select',
+      options: [
+        { label: '企業官網', value: 'corporate' },
+        { label: '電商網站', value: 'ecommerce' },
+        { label: '活動頁面', value: 'landing' },
+        { label: '品牌網站', value: 'brand' },
+        { label: '其他', value: 'other' },
+      ],
+      required: true,
+    },
+    {
+      name: 'tags',
+      type: 'array',
+      fields: [
+        {
+          name: 'tag',
+          type: 'text',
+        },
+      ],
+    },
+    ...slugField(),
+  ],
+  versions: {
+    drafts: {
+      autosave: true,
+    },
+    maxPerDoc: 10,
+  },
+}