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/psr/log/Psr/Log/LoggerInterface.php

@@ -0,0 +1,117 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Gcp\Psr\Log;
+
+/**
+ * Describes a logger instance.
+ *
+ * The message MUST be a string or object implementing __toString().
+ *
+ * The message MAY contain placeholders in the form: {foo} where foo
+ * will be replaced by the context data in key "foo".
+ *
+ * The context array can contain arbitrary data. The only assumption that
+ * can be made by implementors is that if an Exception instance is given
+ * to produce a stack trace, it MUST be in a key named "exception".
+ *
+ * See https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-3-logger-interface.md
+ * for the full interface specification.
+ */
+interface LoggerInterface
+{
+    /**
+     * System is unusable.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function emergency($message, array $context = array());
+    /**
+     * Action must be taken immediately.
+     *
+     * Example: Entire website down, database unavailable, etc. This should
+     * trigger the SMS alerts and wake you up.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function alert($message, array $context = array());
+    /**
+     * Critical conditions.
+     *
+     * Example: Application component unavailable, unexpected exception.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function critical($message, array $context = array());
+    /**
+     * Runtime errors that do not require immediate action but should typically
+     * be logged and monitored.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function error($message, array $context = array());
+    /**
+     * Exceptional occurrences that are not errors.
+     *
+     * Example: Use of deprecated APIs, poor use of an API, undesirable things
+     * that are not necessarily wrong.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function warning($message, array $context = array());
+    /**
+     * Normal but significant events.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function notice($message, array $context = array());
+    /**
+     * Interesting events.
+     *
+     * Example: User logs in, SQL logs.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function info($message, array $context = array());
+    /**
+     * Detailed debug information.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function debug($message, array $context = array());
+    /**
+     * Logs with an arbitrary level.
+     *
+     * @param mixed   $level
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     *
+     * @throws \Psr\Log\InvalidArgumentException
+     */
+    public function log($level, $message, array $context = array());
+}