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/google/common-protos/metadata/Rpc/Context/AttributeContext.php

@@ -0,0 +1,104 @@
+<?php
+
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: google/rpc/context/attribute_context.proto
+namespace DeliciousBrains\WP_Offload_Media\Gcp\GPBMetadata\Google\Rpc\Context;
+
+class AttributeContext
+{
+    public static $is_initialized = \false;
+    public static function initOnce()
+    {
+        $pool = \DeliciousBrains\WP_Offload_Media\Gcp\Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+        if (static::$is_initialized == \true) {
+            return;
+        }
+        \DeliciousBrains\WP_Offload_Media\Gcp\GPBMetadata\Google\Protobuf\Any::initOnce();
+        \DeliciousBrains\WP_Offload_Media\Gcp\GPBMetadata\Google\Protobuf\Duration::initOnce();
+        \DeliciousBrains\WP_Offload_Media\Gcp\GPBMetadata\Google\Protobuf\Struct::initOnce();
+        \DeliciousBrains\WP_Offload_Media\Gcp\GPBMetadata\Google\Protobuf\Timestamp::initOnce();
+        $pool->internalAddGeneratedFile('
+»
+*google/rpc/context/attribute_context.protogoogle.rpc.contextgoogle/protobuf/duration.protogoogle/protobuf/struct.protogoogle/protobuf/timestamp.proto"ƒ
+AttributeContext9
+origin 
(2).google.rpc.context.AttributeContext.Peer9
+source
 
(2).google.rpc.context.AttributeContext.Peer>
+destination 
(2).google.rpc.context.AttributeContext.Peer=
+request 
(2,.google.rpc.context.AttributeContext.Request?
+response 
(2-.google.rpc.context.AttributeContext.Response?
+resource 
(2-.google.rpc.context.AttributeContext.Resource5
+api 
(2(.google.rpc.context.AttributeContext.Api(
+
+extensions (2.google.protobuf.Any¾

+Peer
+
+ip
 
(	
+port 
(E
+labels (25.google.rpc.context.AttributeContext.Peer.LabelsEntry
+	principal 
(	
+region_code 
(	-
+LabelsEntry
+key
 
(	
+value 
(	:8
L
+Api
+service
 
(	
+	operation 
(	
+protocol 
(	
+version 
(	
+Auth
+	principal
 
(	
+	audiences (	
+	presenter 
(	\'
+claims 
(2.google.protobuf.Struct
+
+access_levels (	ï
+Request
+
+id
 
(	
+method 
(	J
+headers (29.google.rpc.context.AttributeContext.Request.HeadersEntry
+path 
(	
+host 
(	
+scheme 
(	
+query 
(	(
+time	 
(2.google.protobuf.Timestamp
+size
+ 
(
+protocol 
(	
+reason 
(	7
+auth
+ 
(2).google.rpc.context.AttributeContext.Auth.
+HeadersEntry
+key
 
(	
+value 
(	:8
<1A>
+Response
+code
 
(
+size 
(K
+headers (2:.google.rpc.context.AttributeContext.Response.HeadersEntry(
+time 
(2.google.protobuf.Timestamp2
+backend_latency 
(2.google.protobuf.Duration.
+HeadersEntry
+key
 
(	
+value 
(	:8
<1A>
+Resource
+service
 
(	
+name 
(	
+type 
(	I
+labels (29.google.rpc.context.AttributeContext.Resource.LabelsEntry
+uid 
(	S
+annotations (2>.google.rpc.context.AttributeContext.Resource.AnnotationsEntry
+display_name 
(	/
+create_time 
(2.google.protobuf.Timestamp/
+update_time	 
(2.google.protobuf.Timestamp/
+delete_time
+ 
(2.google.protobuf.Timestamp
+etag 
(	
+location 
(	-
+LabelsEntry
+key
 
(	
+value 
(	:8
2
+AnnotationsEntry
+key
 
(	
+value 
(	:8
B‹

+com.google.rpc.contextBAttributeContextProtoP
ZUgoogle.golang.org/genproto/googleapis/rpc/context/attribute_context;attribute_contextø

bproto3', \true);
+        static::$is_initialized = \true;