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/Gcp/autoload.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Gcp;
+
+// autoload.php @generated by Composer
+if (\PHP_VERSION_ID < 50600) {
+    if (!\headers_sent()) {
+        \header('HTTP/1.1 500 Internal Server Error');
+    }
+    $err = 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running ' . \PHP_VERSION . ', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.' . \PHP_EOL;
+    if (!\ini_get('display_errors')) {
+        if (\PHP_SAPI === 'cli' || \PHP_SAPI === 'phpdbg') {
+            \fwrite(\STDERR, $err);
+        } elseif (!\headers_sent()) {
+            echo $err;
+        }
+    }
+    \trigger_error($err, \E_USER_ERROR);
+}
+require_once __DIR__ . '/composer/autoload_real.php';
+return ComposerAutoloaderInit70b5f975990d46b5c7c90dc9717b8578::getLoader();