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/HasDataTrait.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Aws3\Aws;
+
+/**
+ * Trait implementing ToArrayInterface, \ArrayAccess, \Countable, and
+ * \IteratorAggregate
+ */
+trait HasDataTrait
+{
+    /** @var array */
+    private $data = [];
+    /**
+     * @return \Traversable
+     */
+    #[\ReturnTypeWillChange]
+    public function getIterator()
+    {
+        return new \ArrayIterator($this->data);
+    }
+    /**
+     * This method returns a reference to the variable to allow for indirect
+     * array modification (e.g., $foo['bar']['baz'] = 'qux').
+     *
+     * @param $offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function &offsetGet($offset)
+    {
+        if (isset($this->data[$offset])) {
+            return $this->data[$offset];
+        }
+        $value = null;
+        return $value;
+    }
+    /**
+     * @return void
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetSet($offset, $value)
+    {
+        $this->data[$offset] = $value;
+    }
+    /**
+     * @return bool
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetExists($offset)
+    {
+        return isset($this->data[$offset]);
+    }
+    /**
+     * @return void
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetUnset($offset)
+    {
+        unset($this->data[$offset]);
+    }
+    public function toArray()
+    {
+        return $this->data;
+    }
+    /**
+     * @return int
+     */
+    #[\ReturnTypeWillChange]
+    public function count()
+    {
+        return \count($this->data);
+    }
+}