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/App/Module/ModuleManifestLoader.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace MintyPHP\App\Module;
+
+use RuntimeException;
+
+/**
+ * Loads a single module manifest from disk without requiring the module to be enabled.
+ *
+ * Unlike ModuleRegistry (which only loads enabled modules), this loader can resolve
+ * any module by its directory — used by validation and deactivation tooling.
+ */
+final class ModuleManifestLoader
+{
+    /**
+     * Load and validate a module manifest from its on-disk location.
+     *
+     * @param string $modulesDir Absolute path to the modules/ directory
+     * @param string $moduleId   Directory name / module ID
+     *
+     * @throws RuntimeException If the manifest file is missing or invalid
+     */
+    public static function loadFromDisk(string $modulesDir, string $moduleId): ModuleManifest
+    {
+        $manifestFile = rtrim($modulesDir, '/') . '/' . $moduleId . '/module.php';
+
+        if (!is_file($manifestFile)) {
+            throw new RuntimeException(
+                "Module manifest not found at: {$manifestFile}"
+            );
+        }
+
+        $raw = require $manifestFile;
+        if (!is_array($raw)) {
+            throw new RuntimeException(
+                "Module manifest at '{$manifestFile}' must return an array."
+            );
+        }
+
+        ModuleManifestSchemaValidator::assertValid($raw, $moduleId, $manifestFile);
+
+        return ModuleManifest::fromArray($raw, dirname($manifestFile));
+    }
+}