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

vendor/Aws3/Aws/ClientSideMonitoring/Configuration.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Aws3\Aws\ClientSideMonitoring;
+
+class Configuration implements ConfigurationInterface
+{
+    private $clientId;
+    private $enabled;
+    private $host;
+    private $port;
+    /**
+     * Constructs a new Configuration object with the specified CSM options set.
+     *
+     * @param mixed $enabled
+     * @param string $host
+     * @param string|int $port
+     * @param string $clientId
+     */
+    public function __construct($enabled, $host, $port, $clientId = '')
+    {
+        $this->host = $host;
+        $this->port = \filter_var($port, \FILTER_VALIDATE_INT);
+        if ($this->port === \false) {
+            throw new \InvalidArgumentException("CSM 'port' value must be an integer!");
+        }
+        // Unparsable $enabled flag errors on the side of disabling CSM
+        $this->enabled = \filter_var($enabled, \FILTER_VALIDATE_BOOLEAN);
+        $this->clientId = \trim($clientId);
+    }
+    /**
+     * {@inheritdoc}
+     */
+    public function isEnabled()
+    {
+        return $this->enabled;
+    }
+    /**
+     * {@inheritdoc}
+     */
+    public function getClientId()
+    {
+        return $this->clientId;
+    }
+    /**
+     * /{@inheritdoc}
+     */
+    public function getHost()
+    {
+        return $this->host;
+    }
+    /**
+     * {@inheritdoc}
+     */
+    public function getPort()
+    {
+        return $this->port;
+    }
+    /**
+     * {@inheritdoc}
+     */
+    public function toArray()
+    {
+        return ['client_id' => $this->getClientId(), 'enabled' => $this->isEnabled(), 'host' => $this->getHost(), 'port' => $this->getPort()];
+    }
+}