Add initial plugin implementation and development setup

src/utils/buildFields.ts

@@ -0,0 +1,43 @@
+import type { Field } from 'payload'
+import type { NotificationRelationship } from '../types'
+
+/**
+ * Builds relationship fields dynamically based on plugin configuration
+ * Creates individual relationship fields within an attachments group
+ */
+export function buildRelationshipFields(relationships: NotificationRelationship[]): Field[] {
+  if (!relationships || relationships.length === 0) {
+    return []
+  }
+
+  // Create individual relationship fields
+  const relationshipFields: Field[] = relationships.map((rel) => {
+    const baseField = {
+      name: rel.name,
+      type: 'relationship' as const,
+      relationTo: rel.relationTo,
+      label: rel.label || `Related ${rel.relationTo}`,
+      required: rel.required || false,
+    }
+
+    // Add hasMany conditionally to satisfy the type constraints
+    if (rel.hasMany) {
+      return {
+        ...baseField,
+        hasMany: true,
+      }
+    }
+
+    return baseField
+  })
+
+  // Wrap relationship fields in a group called "attachments"
+  return [
+    {
+      name: 'attachments',
+      type: 'group',
+      label: 'Attachments',
+      fields: relationshipFields,
+    },
+  ]
+}