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/grpc-gcp/cloudprober/cloudprober.cfg

@@ -0,0 +1,31 @@
+probe {
+  type: EXTERNAL
+  name: "spanner"
+  interval_msec: 1800000
+  timeout_msec: 30000
+  targets { dummy_targets {} }  # No targets for external probe
+  external_probe {
+    mode: ONCE
+    command: "php grpc_gpc_prober/prober.php --api=spanner"
+  }
+}
+
+probe {
+  type: EXTERNAL
+  name: "firestore"
+  interval_msec: 1800000
+  timeout_msec: 30000
+  targets { dummy_targets {} }  # No targets for external probe
+  external_probe {
+    mode: ONCE
+    command: "php grpc_gpc_prober/prober.php --api=firestore"
+  }
+}
+
+surfacer {
+  type: STACKDRIVER
+  name: "stackdriver"
+  stackdriver_surfacer {
+    monitoring_url: "custom.googleapis.com/cloudprober/"
+  }
+}

vendor/Gcp/google/grpc-gcp/cloudprober/codegen.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+cd "$(dirname "$0")"
+
+rm -rf google
+
+for p in $(find ../third_party/googleapis/google -type f -name *.proto); do
+	protoc \
+    --proto_path=../third_party/googleapis \
+    --php_out=./ \
+    --grpc_out=./ \
+    --plugin=protoc-gen-grpc="$(which grpc_php_plugin)" \
+    "$p"
+done

vendor/Gcp/google/grpc-gcp/cloudprober/grpc_gpc_prober/firestore_probes.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Gcp;
+
+require '../vendor/autoload.php';
+$_PARENT_RESOURCE = 'projects/grpc-prober-testing/databases/(default)/documents';
+/*
+Probes to test ListDocuments grpc call from Firestore stub.
+
+  Args:
+    stub: An object of FirestoreStub.
+    metrics: A dict of metrics.
+*/
+function document($client, &$metrics)
+{
+    global $_PARENT_RESOURCE;
+    $list_document_request = new Google\Cloud\Firestore\V1beta1\ListDocumentsRequest();
+    $list_document_request->setParent($_PARENT_RESOURCE);
+    $time_start = microtime_float();
+    $client->ListDocuments($list_document_request);
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['list_documents_latency_ms'] = $lantency;
+}
+$probFunctions = ['documents' => 'document'];
+return $probFunctions;

vendor/Gcp/google/grpc-gcp/cloudprober/grpc_gpc_prober/prober.php

@@ -0,0 +1,85 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Gcp;
+
+\chdir(\dirname(__FILE__));
+require '../vendor/autoload.php';
+// require_once '../Google/Cloud/Firestore/V1beta1/FirestoreClient.php';
+// require_once '../Google/Cloud/Spanner/V1/SpannerClient.php';
+$firestore_probes = (require './firestore_probes.php');
+$spanner_probes = (require './spanner_probes.php');
+require './stackdriver_util.php';
+$_OAUTH_SCOPE = 'https://www.googleapis.com/auth/cloud-platform';
+$_FIRESTORE_TARGET = 'firestore.googleapis.com:443';
+$_SPANNER_TARGET = 'spanner.googleapis.com:443';
+use DeliciousBrains\WP_Offload_Media\Gcp\Google\Auth\ApplicationDefaultCredentials;
+use DeliciousBrains\WP_Offload_Media\Gcp\Google\Cloud\Firestore\V1beta1\FirestoreGrpcClient;
+use DeliciousBrains\WP_Offload_Media\Gcp\Google\Cloud\Spanner\V1\SpannerGrpcClient;
+function getArgs()
+{
+    $options = \getopt('', ['api:', 'extension:']);
+    return $options;
+}
+/*
+function secureAuthorizedChannel($credentials, $request, $target, $kwargs){
+	$metadata_plugin = $transport_grpc->AuthMetadataPlugin($credentials, $request);
+	$ssl_credentials = Grpc\ChannelCredentials::createSsl();
+	$composit_credentials = $grpc->composite_channel_credentials($ssl_credentials, $google_auth_credentials);
+	return $grpc_gcp->secure_channel($target, $composit_credentials, $kwargs);
+}
+
+function getStubChannel($target){
+	$res = $auth->default([$_OAUTH_SCOPE]);
+	$cred = $res[0];
+	return secureAuthorizedChannel($cred, Request(), $target);
+}*/
+function executeProbes($api)
+{
+    global $_OAUTH_SCOPE;
+    global $_SPANNER_TARGET;
+    global $_FIRESTORE_TARGET;
+    global $spanner_probes;
+    global $firestore_probes;
+    $util = new StackdriverUtil($api);
+    $auth = Google\Auth\ApplicationDefaultCredentials::getCredentials($_OAUTH_SCOPE);
+    $opts = ['credentials' => \Grpc\ChannelCredentials::createSsl(), 'update_metadata' => $auth->getUpdateMetadataFunc()];
+    if ($api == 'spanner') {
+        $client = new SpannerGrpcClient($_SPANNER_TARGET, $opts);
+        $probe_functions = $spanner_probes;
+    } else {
+        if ($api == 'firestore') {
+            $client = new FirestoreGrpcClient($_FIRESTORE_TARGET, $opts);
+            $probe_functions = $firestore_probes;
+        } else {
+            echo 'grpc not implemented for ' . $api;
+            exit(1);
+        }
+    }
+    $total = \sizeof($probe_functions);
+    $success = 0;
+    $metrics = [];
+    # Execute all probes for given api
+    foreach ($probe_functions as $probe_name => $probe_function) {
+        try {
+            $probe_function($client, $metrics);
+            $success++;
+        } catch (\Exception $e) {
+            $util->reportError($e);
+        }
+    }
+    if ($success == $total) {
+        $util->setSuccess(\DeliciousBrains\WP_Offload_Media\Gcp\True);
+    }
+    $util->addMetrics($metrics);
+    $util->outputMetrics();
+    if ($success != $total) {
+        # TODO: exit system
+        exit(1);
+    }
+}
+function main()
+{
+    $args = getArgs();
+    executeProbes($args['api']);
+}
+main();

vendor/Gcp/google/grpc-gcp/cloudprober/grpc_gpc_prober/spanner_probes.php

@@ -0,0 +1,245 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Gcp;
+
+require '../vendor/autoload.php';
+$_DATABASE = 'projects/grpc-prober-testing/instances/test-instance/databases/test-db';
+$_TEST_USERNAME = 'test_username';
+function hardAssert($value, $error_message)
+{
+    if (!$value) {
+        echo $error_message . "\n";
+        exit(1);
+    }
+}
+function hardAssertIfStatusOk($status)
+{
+    if ($status->code !== \Grpc\STATUS_OK) {
+        echo "Call did not complete successfully. Status object:\n";
+        \var_dump($status);
+        exit(1);
+    }
+}
+function microtime_float()
+{
+    list($usec, $sec) = \explode(" ", \microtime());
+    return (float) $usec + (float) $sec;
+}
+/*
+Probes to test session related grpc call from Spanner stub.
+  Includes tests against CreateSession, GetSession, ListSessions, and
+  DeleteSession of Spanner stub.
+  Args:
+    stub: An object of SpannerStub.
+    metrics: A list of metrics.
+*/
+function sessionManagement($client, &$metrics)
+{
+    global $_DATABASE;
+    $createSessionRequest = new Google\Cloud\Spanner\V1\CreateSessionRequest();
+    $createSessionRequest->setDatabase($_DATABASE);
+    #Create Session test
+    #Create
+    $time_start = microtime_float();
+    list($session, $status) = $client->CreateSession($createSessionRequest)->wait();
+    hardAssertIfStatusOk($status);
+    hardAssert($session !== null, 'Call completed with a null response');
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['create_session_latency_ms'] = $lantency;
+    #Get Session
+    $getSessionRequest = new Google\Cloud\Spanner\V1\GetSessionRequest();
+    $getSessionRequest->setName($session->getName());
+    $time_start = microtime_float();
+    $response = $client->GetSession($getSessionRequest);
+    $response->wait();
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['get_session_latency_ms'] = $lantency;
+    #List session
+    $listSessionsRequest = new Google\Cloud\Spanner\V1\ListSessionsRequest();
+    $listSessionsRequest->setDatabase($_DATABASE);
+    $time_start = microtime_float();
+    $response = $client->ListSessions($listSessionsRequest);
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['list_sessions_latency_ms'] = $lantency;
+    #Delete session
+    $deleteSessionRequest = new Google\Cloud\Spanner\V1\DeleteSessionRequest();
+    $deleteSessionRequest->setName($session->getName());
+    $time_start = microtime_float();
+    $client->deleteSession($deleteSessionRequest);
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['delete_session_latency_ms'] = $lantency;
+}
+/*
+Probes to test ExecuteSql and ExecuteStreamingSql call from Spanner stub.
+  Args:
+    stub: An object of SpannerStub.
+    metrics: A list of metrics.
+*/
+function executeSql($client, &$metrics)
+{
+    global $_DATABASE;
+    $createSessionRequest = new Google\Cloud\Spanner\V1\CreateSessionRequest();
+    $createSessionRequest->setDatabase($_DATABASE);
+    list($session, $status) = $client->CreateSession($createSessionRequest)->wait();
+    hardAssertIfStatusOk($status);
+    hardAssert($session !== null, 'Call completed with a null response');
+    # Probing ExecuteSql call
+    $time_start = microtime_float();
+    $executeSqlRequest = new Google\Cloud\Spanner\V1\ExecuteSqlRequest();
+    $executeSqlRequest->setSession($session->getName());
+    $executeSqlRequest->setSql('select * FROM users');
+    $result_set = $client->ExecuteSql($executeSqlRequest);
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['execute_sql_latency_ms'] = $lantency;
+    // TODO: Error check result_set
+    # Probing ExecuteStreamingSql call
+    $partial_result_set = $client->ExecuteStreamingSql($executeSqlRequest);
+    $time_start = microtime_float();
+    $first_result = \array_values($partial_result_set->getMetadata())[0];
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['execute_streaming_sql_latency_ms'] = $lantency;
+    // TODO: Error Check for sreaming sql first result
+    $deleteSessionRequest = new Google\Cloud\Spanner\V1\DeleteSessionRequest();
+    $deleteSessionRequest->setName($session->getName());
+    $client->deleteSession($deleteSessionRequest);
+}
+/*
+Probe to test Read and StreamingRead grpc call from Spanner stub.
+
+  Args:
+    stub: An object of SpannerStub.
+    metrics: A list of metrics.
+*/
+function read($client, &$metrics)
+{
+    global $_DATABASE;
+    $createSessionRequest = new Google\Cloud\Spanner\V1\CreateSessionRequest();
+    $createSessionRequest->setDatabase($_DATABASE);
+    list($session, $status) = $client->CreateSession($createSessionRequest)->wait();
+    hardAssertIfStatusOk($status);
+    hardAssert($session !== null, 'Call completed with a null response');
+    # Probing Read call
+    $time_start = microtime_float();
+    $readRequest = new Google\Cloud\Spanner\V1\ReadRequest();
+    $readRequest->setSession($session->getName());
+    $readRequest->setTable('users');
+    $readRequest->setColumns(['username', 'firstname', 'lastname']);
+    $keyset = new Google\Cloud\Spanner\V1\KeySet();
+    $keyset->setAll(\DeliciousBrains\WP_Offload_Media\Gcp\True);
+    $readRequest->setKeySet($keyset);
+    $result_set = $client->Read($readRequest);
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['read_latency_ms'] = $lantency;
+    // TODO: Error Check for result_set
+    # Probing StreamingRead call
+    $partial_result_set = $client->StreamingRead($readRequest);
+    $time_start = microtime_float();
+    $first_result = \array_values($partial_result_set->getMetadata())[0];
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['streaming_read_latency_ms'] = $lantency;
+    //TODO: Error Check for streaming read first result
+    $deleteSessionRequest = new Google\Cloud\Spanner\V1\DeleteSessionRequest();
+    $deleteSessionRequest->setName($session->getName());
+    $client->deleteSession($deleteSessionRequest);
+}
+/*
+Probe to test BeginTransaction, Commit and Rollback grpc from Spanner stub.
+
+  Args:
+    stub: An object of SpannerStub.
+    metrics: A list of metrics.
+*/
+function transaction($client, &$metrics)
+{
+    global $_DATABASE;
+    $createSessionRequest = new Google\Cloud\Spanner\V1\CreateSessionRequest();
+    $createSessionRequest->setDatabase($_DATABASE);
+    list($session, $status) = $client->CreateSession($createSessionRequest)->wait();
+    hardAssertIfStatusOk($status);
+    hardAssert($session !== null, 'Call completed with a null response');
+    $txn_options = new Google\Cloud\Spanner\V1\TransactionOptions();
+    $rw = new Google\Cloud\Spanner\V1\TransactionOptions\ReadWrite();
+    $txn_options->setReadWrite($rw);
+    $txn_request = new Google\Cloud\Spanner\V1\BeginTransactionRequest();
+    $txn_request->setSession($session->getName());
+    $txn_request->setOptions($txn_options);
+    # Probing BeginTransaction call
+    $time_start = microtime_float();
+    list($txn, $status) = $client->BeginTransaction($txn_request)->wait();
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['begin_transaction_latency_ms'] = $lantency;
+    hardAssertIfStatusOk($status);
+    hardAssert($txn !== null, 'Call completed with a null response');
+    # Probing Commit Call
+    $commit_request = new Google\Cloud\Spanner\V1\CommitRequest();
+    $commit_request->setSession($session->getName());
+    $commit_request->setTransactionId($txn->getId());
+    $time_start = microtime_float();
+    $client->Commit($commit_request);
+    $latency = (microtime_float() - $time_start) * 1000;
+    $metrics['commit_latency_ms'] = $lantency;
+    # Probing Rollback call
+    list($txn, $status) = $client->BeginTransaction($txn_request)->wait();
+    $rollback_request = new Google\Cloud\Spanner\V1\RollbackRequest();
+    $rollback_request->setSession($session->getName());
+    $rollback_request->setTransactionId($txn->getId());
+    hardAssertIfStatusOk($status);
+    hardAssert($txn !== null, 'Call completed with a null response');
+    $time_start = microtime_float();
+    $client->Rollback($rollback_request);
+    $latency = (microtime_float() - $time_start) * 1000;
+    $metrics['rollback_latency_ms'] = $latency;
+    $deleteSessionRequest = new Google\Cloud\Spanner\V1\DeleteSessionRequest();
+    $deleteSessionRequest->setName($session->getName());
+    $client->deleteSession($deleteSessionRequest);
+}
+/*
+Probe to test PartitionQuery and PartitionRead grpc call from Spanner stub.
+
+  Args:
+    stub: An object of SpannerStub.
+    metrics: A list of metrics.
+*/
+function partition($client, &$metrics)
+{
+    global $_DATABASE;
+    global $_TEST_USERNAME;
+    $createSessionRequest = new Google\Cloud\Spanner\V1\CreateSessionRequest();
+    $createSessionRequest->setDatabase($_DATABASE);
+    list($session, $status) = $client->CreateSession($createSessionRequest)->wait();
+    hardAssertIfStatusOk($status);
+    hardAssert($session !== null, 'Call completed with a null response');
+    $txn_options = new Google\Cloud\Spanner\V1\TransactionOptions();
+    $ro = new Google\Cloud\Spanner\V1\TransactionOptions\PBReadOnly();
+    $txn_options->setReadOnly($ro);
+    $txn_selector = new Google\Cloud\Spanner\V1\TransactionSelector();
+    $txn_selector->setBegin($txn_options);
+    #Probing PartitionQuery call
+    $ptn_query_request = new Google\Cloud\Spanner\V1\PartitionQueryRequest();
+    $ptn_query_request->setSession($session->getName());
+    $ptn_query_request->setSql('select * FROM users');
+    $ptn_query_request->setTransaction($txn_selector);
+    $time_start = microtime_float();
+    $client->PartitionQuery($ptn_query_request);
+    $lantency = (microtime_float() - $time_start) * 1000;
+    $metrics['partition_query_latency_ms'] = $lantency;
+    #Probing PartitionRead call
+    $ptn_read_request = new Google\Cloud\Spanner\V1\PartitionReadRequest();
+    $ptn_read_request->setSession($session->getName());
+    $ptn_read_request->setTable('users');
+    $ptn_read_request->setTransaction($txn_selector);
+    $keyset = new Google\Cloud\Spanner\V1\KeySet();
+    $keyset->setAll(\DeliciousBrains\WP_Offload_Media\Gcp\True);
+    $ptn_read_request->setKeySet($keyset);
+    $ptn_read_request->setColumns(['username', 'firstname', 'lastname']);
+    $time_start = microtime_float();
+    $client->PartitionRead($ptn_read_request);
+    $latency = (microtime_float() - $time_start) * 1000;
+    $metrics['partition_read_latency_ms'] = $latency;
+    # Delete Session
+    $deleteSessionRequest = new Google\Cloud\Spanner\V1\DeleteSessionRequest();
+    $deleteSessionRequest->setName($session->getName());
+    $client->deleteSession($deleteSessionRequest);
+}
+$PROBE_FUNCTIONS = ['session_management' => 'sessionManagement', 'execute_sql' => 'executeSql', 'read' => 'read', 'transaction' => 'transaction', 'partition' => 'partition'];
+return $PROBE_FUNCTIONS;

vendor/Gcp/google/grpc-gcp/cloudprober/grpc_gpc_prober/stackdriver_util.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace DeliciousBrains\WP_Offload_Media\Gcp;
+
+require '../vendor/autoload.php';
+use DeliciousBrains\WP_Offload_Media\Gcp\Google\Cloud\ErrorReporting\V1beta1\ReportErrorsServiceClient;
+use DeliciousBrains\WP_Offload_Media\Gcp\Google\Cloud\ErrorReporting\V1beta1\ErrorContext;
+use DeliciousBrains\WP_Offload_Media\Gcp\Google\Cloud\ErrorReporting\V1beta1\ReportedErrorEvent;
+use DeliciousBrains\WP_Offload_Media\Gcp\Google\Cloud\ErrorReporting\V1beta1\SourceLocation;
+class StackdriverUtil
+{
+    protected $api;
+    protected $metrics;
+    protected $success;
+    protected $err_client;
+    function __construct($api)
+    {
+        $this->api = $api;
+        $this->metrics = [];
+        $this->success = \FALSE;
+        $this->err_client = new ReportErrorsServiceClient();
+    }
+    function addMetric($key, $value)
+    {
+        $this->matrics[$key] = $value;
+    }
+    function addMetrics($metrics)
+    {
+        $this->metrics = \array_merge($metrics, $this->metrics);
+    }
+    function setSuccess($result)
+    {
+        $this->success = $result;
+    }
+    function outputMetrics()
+    {
+        if ($this->success) {
+            echo $this->api . '_success 1' . "\n";
+        } else {
+            echo $this->api . '_success 0' . "\n";
+        }
+        foreach ($this->metrics as $key => $value) {
+            echo $key . ' ' . $value . "\n";
+        }
+    }
+    function reportError($err)
+    {
+        \error_log($err);
+        $projectId = '434076015357';
+        $project_name = $this->err_client->projectName($projectId);
+        $location = (new SourceLocation())->setFunctionName($this->api);
+        $context = (new ErrorContext())->setReportLocation($location);
+        $error_event = new ReportedErrorEvent();
+        $error_event->setMessage('PHPProbeFailure: fails on ' . $this->api . ' API. Details: ' . (string) $err . "\n");
+        $error_event->setContext($context);
+        $this->err_client->reportErrorEvent($project_name, $error_event);
+    }
+}