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/ResultInterface.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Aws3\Aws;
+
+/**
+ * Represents an AWS result object that is returned from executing an operation.
+ */
+interface ResultInterface extends \ArrayAccess, \IteratorAggregate, \Countable
+{
+    /**
+     * Provides debug information about the result object
+     *
+     * @return string
+     */
+    public function __toString();
+    /**
+     * Convert the result to an array.
+     *
+     * @return array
+     */
+    public function toArray();
+    /**
+     * Check if the model contains a key by name
+     *
+     * @param string $name Name of the key to retrieve
+     *
+     * @return bool
+     */
+    public function hasKey($name);
+    /**
+     * Get a specific key value from the result model.
+     *
+     * @param string $key Key to retrieve.
+     *
+     * @return mixed|null Value of the key or NULL if not found.
+     */
+    public function get($key);
+    /**
+     * Returns the result of executing a JMESPath expression on the contents
+     * of the Result model.
+     *
+     *     $result = $client->execute($command);
+     *     $jpResult = $result->search('foo.*.bar[?baz > `10`]');
+     *
+     * @param string $expression JMESPath expression to execute
+     *
+     * @return mixed Returns the result of the JMESPath expression.
+     * @link http://jmespath.readthedocs.org/en/latest/ JMESPath documentation
+     */
+    public function search($expression);
+}