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/background-processes/download-and-remover-process.php

@@ -0,0 +1,94 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Pro\Background_Processes;
+
+use DeliciousBrains\WP_Offload_Media\Items\Item;
+use DeliciousBrains\WP_Offload_Media\Pro\Items\Remove_Provider_Handler;
+use Exception;
+
+class Download_And_Remover_Process extends Downloader_Process {
+
+	/**
+	 * @var string
+	 */
+	protected $action = 'download_and_remover';
+
+	/**
+	 * Download and remove the item from bucket.
+	 *
+	 * @param string $source_type
+	 * @param int    $source_id
+	 * @param int    $blog_id
+	 *
+	 * @return bool
+	 * @throws Exception
+	 */
+	protected function handle_item( $source_type, $source_id, $blog_id ) {
+		if ( parent::handle_item( $source_type, $source_id, $blog_id ) ) {
+			/** @var Item $class */
+			$class      = $this->as3cf->get_source_type_class( $source_type );
+			$as3cf_item = $class::get_by_source_id( $source_id );
+
+			/** @var Remove_Provider_Handler $remove_handler */
+			$remove_handler = $this->as3cf->get_item_handler( Remove_Provider_Handler::get_item_handler_key_name() );
+
+			// As we've already confirmed that local files exist,
+			// and not had to record any errors for display,
+			// we can skip confirming that files exist on local,
+			// or that the remove from provider succeeded.
+			$result = $remove_handler->handle( $as3cf_item, array( 'verify_exists_on_local' => false ) );
+
+			if ( is_wp_error( $result ) ) {
+				foreach ( $result->get_error_messages() as $error_message ) {
+					$error_msg = sprintf( __( 'Error removing from bucket - %s', 'amazon-s3-and-cloudfront' ), $error_message );
+					$this->record_error( $blog_id, $source_type, $source_id, $error_msg );
+				}
+
+				return false;
+			}
+
+			$as3cf_item->delete();
+
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Called when background process has been cancelled.
+	 */
+	protected function cancelled() {
+		$this->as3cf->update_media_library_total();
+	}
+
+	/**
+	 * Called when background process has been paused.
+	 */
+	protected function paused() {
+		$this->as3cf->update_media_library_total();
+	}
+
+	/**
+	 * Called when background process has been resumed.
+	 */
+	protected function resumed() {
+		// Do nothing at the moment.
+	}
+
+	/**
+	 * Called when background process has completed.
+	 */
+	protected function completed() {
+		$this->as3cf->update_media_library_total();
+	}
+
+	/**
+	 * Get complete notice message.
+	 *
+	 * @return string
+	 */
+	protected function get_complete_message() {
+		return __( 'Finished removing media files from bucket.', 'amazon-s3-and-cloudfront' );
+	}
+}