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/EndpointDiscovery/EndpointList.php

@@ -0,0 +1,80 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Aws3\Aws\EndpointDiscovery;
+
+class EndpointList
+{
+    private $active;
+    private $expired = [];
+    public function __construct(array $endpoints)
+    {
+        $this->active = $endpoints;
+        \reset($this->active);
+    }
+    /**
+     * Gets an active (unexpired) endpoint. Returns null if none found.
+     *
+     * @return null|string
+     */
+    public function getActive()
+    {
+        if (\count($this->active) < 1) {
+            return null;
+        }
+        while (\time() > \current($this->active)) {
+            $key = \key($this->active);
+            $this->expired[$key] = \current($this->active);
+            $this->increment($this->active);
+            unset($this->active[$key]);
+            if (\count($this->active) < 1) {
+                return null;
+            }
+        }
+        $active = \key($this->active);
+        $this->increment($this->active);
+        return $active;
+    }
+    /**
+     * Gets an active endpoint if possible, then an expired endpoint if possible.
+     * Returns null if no endpoints found.
+     *
+     * @return null|string
+     */
+    public function getEndpoint()
+    {
+        if (!empty($active = $this->getActive())) {
+            return $active;
+        }
+        return $this->getExpired();
+    }
+    /**
+     * Removes an endpoint from both lists.
+     *
+     * @param string $key
+     */
+    public function remove($key)
+    {
+        unset($this->active[$key]);
+        unset($this->expired[$key]);
+    }
+    /**
+     * Get an expired endpoint. Returns null if none found.
+     *
+     * @return null|string
+     */
+    private function getExpired()
+    {
+        if (\count($this->expired) < 1) {
+            return null;
+        }
+        $expired = \key($this->expired);
+        $this->increment($this->expired);
+        return $expired;
+    }
+    private function increment(&$array)
+    {
+        if (\next($array) === \false) {
+            \reset($array);
+        }
+    }
+}