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/upgrades/upgrade-clear-postmeta-cache.php

@@ -0,0 +1,113 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Upgrades;
+
+/**
+ * Clear_Postmeta_Cache Class
+ *
+ * This class clears the postmeta cache after upgrade to 2.6.1
+ *
+ * @since 2.6.1
+ */
+class Upgrade_Clear_Postmeta_Cache extends Upgrade {
+
+	/**
+	 * @var int
+	 */
+	protected $upgrade_id = 11;
+
+	/**
+	 * @var string
+	 */
+	protected $upgrade_name = 'clear_postmeta_cache';
+
+	/**
+	 * @var string 'metadata', 'attachment'
+	 */
+	protected $upgrade_type = 'metadata';
+
+	/**
+	 * @var int
+	 */
+	private $batch_limit = 1000;
+
+	/**
+	 * Get running update text.
+	 *
+	 * @return string
+	 */
+	protected function get_running_update_text() {
+		return __( 'and clear old post meta cache items.', 'amazon-s3-and-cloudfront' );
+	}
+
+	/**
+	 * Remove one chunk of post meta cache records.
+	 *
+	 * @param string $item Table prefix for the current blog.
+	 *
+	 * @return bool
+	 */
+	protected function upgrade_item( $item ) {
+		global $wpdb;
+
+		$sql = "DELETE FROM {$item}postmeta WHERE meta_key = 'amazonS3_cache' AND meta_id <= %d LIMIT {$this->batch_limit}";
+		$wpdb->query( $wpdb->prepare( $sql, array( $this->session[ $item ] ) ) );
+
+		return true;
+	}
+
+	/**
+	 * Count items left to process for the current blog.
+	 *
+	 * @return int
+	 */
+	protected function count_items_to_process() {
+		global $wpdb;
+
+		// Store the highest known meta_id at the time we begin processing.
+		if ( empty( $this->session[ $this->blog_prefix ] ) ) {
+			$sql  = "SELECT meta_id FROM {$this->blog_prefix}postmeta WHERE meta_key = 'amazonS3_cache' ORDER BY meta_id DESC LIMIT 0, 1;";
+			$last = $wpdb->get_var( $sql );
+
+			$this->session[ $this->blog_prefix ] = $last;
+		}
+
+		return count( $this->get_items_to_process( $this->blog_prefix, 0 ) );
+	}
+
+	/**
+	 * Get array of items that each represent one chunk to be cleared.
+	 *
+	 * @param string     $prefix Table prefix for blog.
+	 * @param int        $limit
+	 * @param bool|mixed $offset
+	 *
+	 * @return array
+	 */
+	protected function get_items_to_process( $prefix, $limit, $offset = false ) {
+		$count = $this->get_real_count( $prefix );
+		if ( 0 === $count ) {
+			return array();
+		}
+
+		$chunks = ceil( $count / $this->batch_limit );
+
+		return array_fill( 0, $chunks, $prefix );
+	}
+
+	/**
+	 * Return the real number of remaining amazonS3_cache items to clear out.
+	 *
+	 * @param string $prefix
+	 *
+	 * @return int
+	 */
+	private function get_real_count( $prefix ) {
+		global $wpdb;
+
+		$sql   = "SELECT count(meta_id) FROM {$prefix}postmeta WHERE meta_key = 'amazonS3_cache' AND meta_id <= %d";
+		$count = $wpdb->get_var( $wpdb->prepare( $sql, $this->session[ $prefix ] ) );
+
+		return (int) $count;
+	}
+}