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/AbstractLogger.php

@@ -0,0 +1,121 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Gcp\Psr\Log;
+
+/**
+ * This is a simple Logger implementation that other Loggers can inherit from.
+ *
+ * It simply delegates all log-level-specific methods to the `log` method to
+ * reduce boilerplate code that a simple Logger that does the same thing with
+ * messages regardless of the error level has to implement.
+ */
+abstract class AbstractLogger implements LoggerInterface
+{
+    /**
+     * System is unusable.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function emergency($message, array $context = array())
+    {
+        $this->log(LogLevel::EMERGENCY, $message, $context);
+    }
+    /**
+     * 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())
+    {
+        $this->log(LogLevel::ALERT, $message, $context);
+    }
+    /**
+     * Critical conditions.
+     *
+     * Example: Application component unavailable, unexpected exception.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function critical($message, array $context = array())
+    {
+        $this->log(LogLevel::CRITICAL, $message, $context);
+    }
+    /**
+     * 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())
+    {
+        $this->log(LogLevel::ERROR, $message, $context);
+    }
+    /**
+     * 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())
+    {
+        $this->log(LogLevel::WARNING, $message, $context);
+    }
+    /**
+     * Normal but significant events.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function notice($message, array $context = array())
+    {
+        $this->log(LogLevel::NOTICE, $message, $context);
+    }
+    /**
+     * Interesting events.
+     *
+     * Example: User logs in, SQL logs.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function info($message, array $context = array())
+    {
+        $this->log(LogLevel::INFO, $message, $context);
+    }
+    /**
+     * Detailed debug information.
+     *
+     * @param string  $message
+     * @param mixed[] $context
+     *
+     * @return void
+     */
+    public function debug($message, array $context = array())
+    {
+        $this->log(LogLevel::DEBUG, $message, $context);
+    }
+}