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/Api/ShapeMap.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Aws3\Aws\Api;
+
+/**
+ * Builds shape based on shape references.
+ */
+class ShapeMap
+{
+    /** @var array */
+    private $definitions;
+    /** @var Shape[] */
+    private $simple;
+    /**
+     * @param array $shapeModels Associative array of shape definitions.
+     */
+    public function __construct(array $shapeModels)
+    {
+        $this->definitions = $shapeModels;
+    }
+    /**
+     * Get an array of shape names.
+     *
+     * @return array
+     */
+    public function getShapeNames()
+    {
+        return \array_keys($this->definitions);
+    }
+    /**
+     * Resolve a shape reference
+     *
+     * @param array $shapeRef Shape reference shape
+     *
+     * @return Shape
+     * @throws \InvalidArgumentException
+     */
+    public function resolve(array $shapeRef)
+    {
+        $shape = $shapeRef['shape'];
+        if (!isset($this->definitions[$shape])) {
+            throw new \InvalidArgumentException('Shape not found: ' . $shape);
+        }
+        $isSimple = \count($shapeRef) == 1;
+        if ($isSimple && isset($this->simple[$shape])) {
+            return $this->simple[$shape];
+        }
+        $definition = $shapeRef + $this->definitions[$shape];
+        $definition['name'] = $definition['shape'];
+        if (isset($definition['shape'])) {
+            unset($definition['shape']);
+        }
+        $result = Shape::create($definition, $this);
+        if ($isSimple) {
+            $this->simple[$shape] = $result;
+        }
+        return $result;
+    }
+}