Fix model overwrite error when plugin is initialized multiple times

- Filter out existing collections with same slugs before adding plugin collections
- Prevents 'Cannot overwrite model once compiled' errors in Next.js apps
- Fixes issue during hot reload and multiple getPayload() calls
- Bump version to 0.1.19

src/payload-types.ts

@@ -143,6 +143,10 @@ export interface Email {
    * Sender email address (optional, uses default if not provided)
    */
   from?: string | null;
+  /**
+   * Sender display name (optional, e.g., "John Doe" for "John Doe <john@example.com>")
+   */
+  fromName?: string | null;
   /**
    * Reply-to email address
    */
@@ -336,6 +340,7 @@ export interface EmailsSelect<T extends boolean = true> {
   cc?: T;
   bcc?: T;
   from?: T;
+  fromName?: T;
   replyTo?: T;
   subject?: T;
   html?: T;