feat: add S3-compatible storage provider (MinIO, Ceph, R2, etc.)

Adds a new 'S3-Compatible Storage' provider that works with any
S3-API-compatible object storage service, including MinIO, Ceph,
Cloudflare R2, Backblaze B2, and others.

Changes:
- New provider class: classes/providers/storage/s3-compatible-provider.php
  - Provider key: s3compatible
  - Reads user-configured endpoint URL from settings
  - Uses path-style URL access (required by most S3-compatible services)
  - Supports credentials via AS3CF_S3COMPAT_ACCESS_KEY_ID /
    AS3CF_S3COMPAT_SECRET_ACCESS_KEY wp-config.php constants
  - Disables AWS-specific features (Block Public Access, Object Ownership)
- New provider SVG icons (s3compatible.svg, -link.svg, -round.svg)
- Registered provider in main plugin class with endpoint setting support
- Updated StorageProviderSubPage to show endpoint URL input for S3-compatible
- Built pro settings bundle with rollup (Svelte 4.2.19)
- Added package.json and updated rollup.config.mjs for pro-only builds

classes/pro/integrations/wpml.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Pro\Integrations;
+
+use DeliciousBrains\WP_Offload_Media\Items\Media_Library_Item;
+use DeliciousBrains\WP_Offload_Media\Integrations\Integration;
+
+class Wpml extends Integration {
+
+	/**
+	 * Is installed?
+	 *
+	 * @return bool
+	 */
+	public static function is_installed(): bool {
+		if ( class_exists( 'SitePress' ) ) {
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Init integration.
+	 */
+	public function init() {
+		// Nothing to do.
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function setup() {
+		add_action( 'wpml_media_create_duplicate_attachment', array( $this, 'duplicate_offloaded_item' ), 10, 2 );
+	}
+
+	/**
+	 * Duplicate original item's offload data for new duplicate Media Library item.
+	 *
+	 * WPML duplicates postmeta in reverse order which unfortunately means we can't catch the new attachment and offload it.
+	 * But, WPML does fire an action after each item is duplicated, so we can just duplicate our data too.
+	 *
+	 * @param int $attachment_id
+	 * @param int $new_attachment_id
+	 */
+	public function duplicate_offloaded_item( $attachment_id, $new_attachment_id ) {
+		$old_item = Media_Library_Item::get_by_source_id( $attachment_id );
+
+		if ( $old_item ) {
+			$as3cf_item = Media_Library_Item::get_by_source_id( $new_attachment_id );
+
+			if ( ! $as3cf_item ) {
+				$as3cf_item = new Media_Library_Item(
+					$old_item->provider(),
+					$old_item->region(),
+					$old_item->bucket(),
+					$old_item->path(),
+					$old_item->is_private(),
+					$new_attachment_id,
+					$old_item->source_path(),
+					wp_basename( $old_item->original_source_path() ),
+					$old_item->extra_info()
+				);
+
+				$as3cf_item->save();
+				$as3cf_item->duplicate_filesize_total( $attachment_id );
+			}
+		}
+	}
+}