Add WOPI discovery service and connection diagnostics

lib/Console/CheckCommand.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace KTXM\ServiceWopi\Console;
+
+use KTXM\ServiceWopi\Discovery\DiscoveryClient;
+use KTXM\ServiceWopi\Discovery\ServerAddress;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+use Throwable;
+
+#[AsCommand(name: 'wopi:check', description: 'Check document server discovery without sending documents or credentials')]
+class CheckCommand extends Command
+{
+    public function __construct(private readonly DiscoveryClient $client) { parent::__construct(); }
+
+    protected function configure(): void
+    {
+        $this->addArgument('server', InputArgument::REQUIRED, 'HTTPS base URL of the document server');
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io = new SymfonyStyle($input, $output);
+        try {
+            $document = $this->client->fetch(new ServerAddress($input->getArgument('server')));
+            $rows = [];
+            $hasDocxView = false;
+            foreach ($document->actions as $action) {
+                $rows[] = [$action->extension, $action->name, implode(', ', $action->requirements) ?: 'none'];
+                $hasDocxView = $hasDocxView || ($action->extension === 'docx'
+                    && $action->name === 'view' && $action->supportedBy([]));
+            }
+            $io->table(['Extension', 'Server action', 'Additional host requirements'], $rows);
+            $io->text('Proof key metadata: ' . ($document->hasProofKeys ? 'present (not yet validated)' : 'absent'));
+            if (!$hasDocxView) {
+                $io->error('No DOCX view action usable by a basic read-only host.');
+                return Command::FAILURE;
+            }
+            $io->success('Discovery supports the planned DOCX viewing flow.');
+            $io->note('This check does not verify editor loading, WOPI callbacks, proof signatures, or saving.');
+            return Command::SUCCESS;
+        } catch (Throwable $error) {
+            $io->error($error->getMessage());
+            return Command::FAILURE;
+        }
+    }
+}