Pin a restore point and keep a note on it

Both live in the catalog on the location, so a new server sees them; the database holds
a local copy for the lists. The retention policy leaves a pinned restore point alone and
does not count it. Available on the restore page and as occ backup:pin and backup:note.

lib/Command/Pin.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Command;
+
+use OCA\NgBackup\Service\PruneService;
+use OCA\NgBackup\Service\TargetService;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class Pin extends Command {
+	public function __construct(
+		private TargetService $targets,
+		private PruneService $prune,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this->setName('backup:pin')
+			->setDescription('Keep a snapshot: the retention policy does not remove a pinned one')
+			->addArgument('target', InputArgument::REQUIRED, 'Location name or id')
+			->addArgument('snapshot', InputArgument::REQUIRED, 'Snapshot id (see backup:list)')
+			->addOption('unpin', null, InputOption::VALUE_NONE, 'Leave the snapshot to the retention policy again');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$unpin = (bool)$input->getOption('unpin');
+		try {
+			$this->prune->setPinned($this->targets->get($input->getArgument('target')), $input->getArgument('snapshot'), !$unpin);
+		} catch (\Throwable $e) {
+			$output->writeln('<error>' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		$output->writeln($unpin ? 'Snapshot unpinned; the retention policy applies to it again.' : 'Snapshot pinned; the retention policy leaves it alone.');
+		return 0;
+	}
+}