feat(policy): add docmdp policy provider

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

lib/Service/Policy/Provider/DocMdp/DocMdpPolicy.php

@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2026 LibreCode coop and contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Libresign\Service\Policy\Provider\DocMdp;
+
+use OCA\Libresign\Enum\DocMdpLevel;
+use OCA\Libresign\Service\Policy\Contract\IPolicyDefinition;
+use OCA\Libresign\Service\Policy\Contract\IPolicyDefinitionProvider;
+use OCA\Libresign\Service\Policy\Model\PolicySpec;
+
+final class DocMdpPolicy implements IPolicyDefinitionProvider {
+	public const KEY = 'docmdp';
+	public const SYSTEM_APP_CONFIG_KEY = 'docmdp_level';
+
+	#[\Override]
+	public function keys(): array {
+		return [
+			self::KEY,
+		];
+	}
+
+	#[\Override]
+	public function get(string|\BackedEnum $policyKey): IPolicyDefinition {
+		return match ($this->normalizePolicyKey($policyKey)) {
+			self::KEY => new PolicySpec(
+				key: self::KEY,
+				defaultSystemValue: DocMdpLevel::NOT_CERTIFIED->value,
+				allowedValues: [
+					DocMdpLevel::NOT_CERTIFIED->value,
+					DocMdpLevel::CERTIFIED_NO_CHANGES_ALLOWED->value,
+					DocMdpLevel::CERTIFIED_FORM_FILLING->value,
+					DocMdpLevel::CERTIFIED_FORM_FILLING_AND_ANNOTATIONS->value,
+				],
+				normalizer: static function (mixed $rawValue): mixed {
+					if ($rawValue instanceof DocMdpLevel) {
+						return $rawValue->value;
+					}
+
+					if (is_int($rawValue)) {
+						return $rawValue;
+					}
+
+					return $rawValue;
+				},
+				appConfigKey: self::SYSTEM_APP_CONFIG_KEY,
+			),
+			default => throw new \InvalidArgumentException('Unknown policy key: ' . $this->normalizePolicyKey($policyKey)),
+		};
+	}
+
+	private function normalizePolicyKey(string|\BackedEnum $policyKey): string {
+		if ($policyKey instanceof \BackedEnum) {
+			return (string)$policyKey->value;
+		}
+
+		return $policyKey;
+	}
+}