feat(policy): six-category policy engine wired into the booking flow

Rules become data instead of code: a clinic can say "laser under 18 requires
parental consent" without a deploy.

Engine
- Policy / PolicyVersionLog entities, closed field/operator/effect lists per
  category (PolicySchema), condition validation at write time
- PolicyResolver: priority -> specificity -> age, combining effects by
  veto / max / sum / union
- A missing fact fails its clause instead of silently passing it
- Policies are drafts until activated, and are versioned rather than edited

Wiring
- selection -> ServiceSelectionValidator
- eligibility + spacing -> BookingPolicyGuard, at hold time not confirm time
- resource + timing -> AppointmentPlanBuilder, including template-less services
- pricing -> PricingEngine, alongside (not replacing) the manual discount

The condition column is named condition_json: `condition` is a MariaDB keyword
and broke every INSERT.

Tests: 17 in tests/Policy including NoPolicyRegressionTest, which pins that a
clinic with no policies sees byte-identical output to task 08.
Docs: docs/api/policy.md (real captured JSON) + docs/architecture/policy-engine.md.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/Policy/ValueObject/PolicyOutcome.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Policy\ValueObject;
+
+/**
+ * نتیجهٔ اعمال یک دسته قانون: اثرهای ترکیب‌شده + ردِ قانون‌هایی که اعمال شدند.
+ *
+ * `appliedPolicies` شناسه **و نسخه** را نگه می‌دارد. فقط شناسه کافی نیست: قانون فردا
+ * نسخهٔ ۲ می‌گیرد و آن‌وقت «چرا این نوبت این قیمت را گرفت؟» جواب اشتباه می‌دهد.
+ */
+final readonly class PolicyOutcome
+{
+    /**
+     * @param array<string, mixed>       $effects        نوعِ اثر => مقدار ترکیب‌شده
+     * @param list<array<string, mixed>> $appliedPolicies
+     * @param list<string>               $forbidReasons  پیام‌های انسانیِ ممنوعیت
+     */
+    public function __construct(
+        public array $effects = [],
+        public array $appliedPolicies = [],
+        public array $forbidReasons = [],
+    ) {}
+
+    public function isForbidden(): bool
+    {
+        return $this->forbidReasons !== [];
+    }
+
+    public function effect(string $type, mixed $default = null): mixed
+    {
+        return $this->effects[$type] ?? $default;
+    }
+
+    public function toArray(): array
+    {
+        return [
+            'effects'          => (object) $this->effects,
+            'applied_policies' => $this->appliedPolicies,
+            'forbidden'        => $this->isForbidden(),
+            'forbid_reasons'   => $this->forbidReasons,
+        ];
+    }
+}