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/AssetDetector.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace MintyPHP\Http;
+
+/**
+ * Detects static asset requests that should bypass locale redirects.
+ */
+class AssetDetector
+{
+    /** File extensions that indicate static assets */
+    private const ASSET_EXTENSIONS = [
+        'css', 'js', 'mjs', 'map',
+        'png', 'jpg', 'jpeg', 'gif', 'svg', 'ico', 'webp',
+        'woff', 'woff2', 'ttf', 'eot',
+        'webmanifest',
+    ];
+
+    /** Path prefixes that indicate static asset directories */
+    private const ASSET_PREFIXES = [
+        'vendor/',
+        'css/',
+        'js/',
+        'favicon/',
+        'brand/',
+    ];
+
+    /**
+     * Check if the given path is a static asset request.
+     */
+    public static function isAssetRequest(string $path): bool
+    {
+        if ($path === '') {
+            return false;
+        }
+
+        // Check file extension
+        if (self::hasAssetExtension($path)) {
+            return true;
+        }
+
+        // Check directory prefix
+        foreach (self::ASSET_PREFIXES as $prefix) {
+            if (str_starts_with($path, $prefix)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private static function hasAssetExtension(string $path): bool
+    {
+        $extension = strtolower(pathinfo($path, PATHINFO_EXTENSION));
+        return $extension !== '' && in_array($extension, self::ASSET_EXTENSIONS, true);
+    }
+}