refactor: rename lib/ to core/ for clearer core-module separation

Rename the top-level lib/ directory to core/ so the project root
immediately communicates which code is core platform and which lives
in modules/. PHP namespaces (MintyPHP\*) are unchanged — only the
Composer PSR-4 path mapping moves from lib/ to core/.

Module-internal lib/ directories (modules/*/lib/) are untouched.

Updated across the full stack:
- composer.json PSR-4 mapping
- bootstrap entry points (web/index.php, bin/*, tests/bootstrap.php)
- tooling configs (phpstan.neon, phpunit.xml, php-cs-fixer)
- 26 architecture contract tests
- enforcement-policy, guard-catalog, quality-gates
- all documentation (CLAUDE.md, README, 25 docs/, .agents/skills/)
- bin/qa-extended.sh search paths
- .claude/settings.local.json permission paths

Workflow: .agents/runs/CORE-LIB-RENAME-001/ (Analyst → Planner →
Executor → Code Review (4 findings fixed) → Security Review →
Acceptance Test → Finalizer)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/Service/Access/AuthorizationService.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace MintyPHP\Service\Access;
+
+use Throwable;
+
+class AuthorizationService
+{
+    /** @var array<int, AuthorizationPolicyInterface> */
+    private array $policies = [];
+
+    /**
+     * @param array<int, AuthorizationPolicyInterface> $policies
+     */
+    public function __construct(array $policies)
+    {
+        foreach ($policies as $policy) {
+            if ($policy instanceof AuthorizationPolicyInterface) {
+                $this->policies[] = $policy;
+            }
+        }
+    }
+
+    public function authorize(string $ability, array $context = []): AuthorizationDecision
+    {
+        // First matching policy wins. No match → 500 (misconfiguration, not a user error).
+        foreach ($this->policies as $policy) {
+            if (!$policy->supports($ability)) {
+                continue;
+            }
+
+            try {
+                return $policy->authorize($ability, $context);
+            } catch (Throwable) {
+                return AuthorizationDecision::deny(500, 'authorization_failed');
+            }
+        }
+
+        return AuthorizationDecision::deny(500, 'authorization_policy_missing');
+    }
+
+    public function allow(string $ability, array $context = []): bool
+    {
+        return $this->authorize($ability, $context)->isAllowed();
+    }
+}