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/Http/RouteRegistrar.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace MintyPHP\Http;
+
+use MintyPHP\App\Module\ModuleRegistry;
+use MintyPHP\Router;
+use RuntimeException;
+
+/**
+ * Registers core + module routes into the runtime router.
+ */
+final class RouteRegistrar
+{
+    public function __construct(private readonly ModuleRegistry $moduleRegistry)
+    {
+    }
+
+    public function register(RouteCatalog $catalog): void
+    {
+        $coreRoutePaths = [];
+        foreach ($catalog->coreRoutes() as $route) {
+            $path = trim($route['path']);
+            $target = trim($route['target']);
+            if ($path === '' || $target === '') {
+                continue;
+            }
+
+            $coreRoutePaths[$path] = $target;
+            Router::addRoute($path, $target);
+        }
+
+        $modulePaths = [];
+        foreach ($this->moduleRegistry->getRoutes() as $route) {
+            $path = trim($route['path']);
+            $target = trim($route['target']);
+            $moduleId = trim($route['module_id']);
+            if ($path === '' || $target === '') {
+                continue;
+            }
+
+            if (isset($coreRoutePaths[$path])) {
+                throw new RuntimeException(
+                    "Module route path conflict: '{$path}' from module '{$moduleId}' collides with core route target '{$coreRoutePaths[$path]}'."
+                );
+            }
+            if (isset($modulePaths[$path])) {
+                throw new RuntimeException(
+                    "Module route path conflict: '{$path}' from module '{$moduleId}' collides with module '{$modulePaths[$path]}'."
+                );
+            }
+
+            $modulePaths[$path] = $moduleId;
+            Router::addRoute($path, $target);
+        }
+    }
+}