feat(config): add modern PSR-4 config loaders

src/Assets/ResponsiveAssets.php

@@ -63,8 +63,8 @@ public function __construct(
     public function getCssUrls(?string $theme = null, ?string $app = null): array
     {
         $urls = [];
-        $theme = $theme ?? $this->getThemePreference();
-        $app = $app ?? $this->registry->getApp();
+        $theme ??= $this->getThemePreference();
+        $app ??= $this->registry->getApp();
 
         $cssFiles = ['responsive.css'];
 
@@ -107,7 +107,7 @@ public function getCssUrls(?string $theme = null, ?string $app = null): array
     public function getJsUrls(array $jsFiles = [], ?string $app = null): array
     {
         $urls = [];
-        $app = $app ?? $this->registry->getApp();
+        $app ??= $this->registry->getApp();
 
         foreach ($jsFiles as $file) {
             // Check Horde base JS

src/Auth/Jwt/GeneratedJwt.php

@@ -27,7 +27,8 @@ public function __construct(
         public readonly string $token,
         public readonly int $expiresAt,
         public readonly array $claims = []
-    ) {}
+    ) {
+    }
 
     /**
      * Get a specific claim value

src/Auth/Jwt/PrivateKey.php

@@ -25,7 +25,8 @@ class PrivateKey
      */
     private function __construct(
         public readonly string $content
-    ) {}
+    ) {
+    }
 
     /**
      * Create from PEM string content

src/Auth/Jwt/VerifiedJwt.php

@@ -25,7 +25,8 @@ class VerifiedJwt
     public function __construct(
         public readonly string $token,
         public readonly array $claims
-    ) {}
+    ) {
+    }
 
     /**
      * Get a specific claim value

src/Config/BackendConfigLoader.php

@@ -0,0 +1,218 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright 2026 The Horde Project (http://www.horde.org/)
+ *
+ * See the enclosed file LICENSE for license information (LGPL). If you
+ * did not receive this file, see http://www.horde.org/licenses/lgpl21.
+ *
+ * @category  Horde
+ * @copyright 2026 The Horde Project
+ * @license   http://www.horde.org/licenses/lgpl21 LGPL 2.1
+ * @package   Core
+ */
+
+namespace Horde\Core\Config;
+
+use RuntimeException;
+
+/**
+ * Backend config loader for Horde applications
+ *
+ * Loads backend definitions from backends.php with support for:
+ * - Vendor defaults (from vendor/horde/$app/config/backends.php)
+ * - Deployment config (from HORDE_CONFIG_BASE/$app/backends.php)
+ * - Config snippets (backends.d/)
+ * - Local overrides (backends.local.php)
+ * - VHost overrides (backends-{hostname}.php)
+ *
+ * Returns BackendState objects, does NOT populate globals.
+ *
+ * @category  Horde
+ * @copyright 2026 The Horde Project
+ * @license   http://www.horde.org/licenses/lgpl21 LGPL 2.1
+ * @package   Core
+ */
+class BackendConfigLoader
+{
+    private array $cache = [];
+
+    public function __construct(
+        private string $configBase,  // HORDE_CONFIG_BASE constant
+        private string $vendorBase,  // Path to vendor/horde/ directory
+        private Vhost|string $vhost = 'localhost'
+    ) {
+        $this->vhost = Vhost::from($this->vhost);
+    }
+
+    /**
+     * Load backend definitions for an app
+     *
+     * @param string $app App name ('passwd', 'imp', 'ingo', etc.)
+     * @param string $file Config filename (default: 'backends.php')
+     * @return BackendState Immutable backend state
+     */
+    public function load(string $app, string $file = 'backends.php'): BackendState
+    {
+        $cacheKey = $app . ':' . $file;
+
+        if (!isset($this->cache[$cacheKey])) {
+            $backends = $this->loadFiles($app, $file);
+            $this->cache[$cacheKey] = new BackendState($backends);
+        }
+
+        return $this->cache[$cacheKey];
+    }
+
+    /**
+     * Load specific layer for introspection
+     *
+     * @param string $app App name
+     * @param string $layer Layer name ('vendor', 'base', 'snippets', 'local', 'vhost')
+     * @param string $file Config filename
+     * @return array Raw config from that layer only
+     */
+    public function loadLayer(string $app, string $layer, string $file = 'backends.php'): array
+    {
+        $pathInfo = pathinfo($file);
+        $confDir = $this->configBase . '/' . $app . '/';
+        $vendorDir = $this->vendorBase . '/' . $app . '/config/';
+
+        switch ($layer) {
+            case 'vendor':
+                $filePath = $vendorDir . $file;
+                return file_exists($filePath) ? $this->includeFile($filePath) : [];
+
+            case 'base':
+                $filePath = $confDir . $file;
+                return file_exists($filePath) ? $this->includeFile($filePath) : [];
+
+            case 'snippets':
+                $snippetsDir = $confDir . $pathInfo['filename'] . '.d';
+                if (!is_dir($snippetsDir)) {
+                    return [];
+                }
+                $snippets = glob($snippetsDir . '/*.php');
+                if ($snippets === false) {
+                    return [];
+                }
+                sort($snippets);
+                $merged = [];
+                foreach ($snippets as $snippetFile) {
+                    $loaded = $this->includeFile($snippetFile);
+                    $merged = array_replace_recursive($merged, $loaded);
+                }
+                return $merged;
+
+            case 'local':
+                $filePath = $confDir . $pathInfo['filename'] . '.local.' . $pathInfo['extension'];
+                return file_exists($filePath) ? $this->includeFile($filePath) : [];
+
+            case 'vhost':
+                // Need to check if vhosts enabled - requires loading base config first
+                // For introspection, just return empty if vhost file doesn't exist
+                $vhostFile = $confDir . $pathInfo['filename'] . '-*.'. $pathInfo['extension'];
+                $vhostFiles = glob($vhostFile);
+                if ($vhostFiles === false || empty($vhostFiles)) {
+                    return [];
+                }
+                // Return first vhost file found (for introspection purposes)
+                return $this->includeFile($vhostFiles[0]);
+
+            default:
+                throw new RuntimeException("Unknown layer: $layer");
+        }
+    }
+
+    /**
+     * Clear cache (useful for testing)
+     */
+    public function clearCache(): void
+    {
+        $this->cache = [];
+    }
+
+    /**
+     * Load and merge backend files
+     *
+     * @param string $app App name
+     * @param string $file Config filename
+     * @return array Merged backends array
+     */
+    private function loadFiles(string $app, string $file): array
+    {
+        $pathInfo = pathinfo($file);
+        $confDir = $this->configBase . '/' . $app . '/';
+        $vendorDir = $this->vendorBase . '/' . $app . '/config/';
+
+        // Build file list
+        $files = [];
+
+        // 1. Vendor defaults (factory defaults)
+        $files[] = $vendorDir . $file;
+
+        // 2. Deployment base config
+        $files[] = $confDir . $file;
+
+        // 3. Config snippets (backends.d/)
+        $snippetsDir = $confDir . $pathInfo['filename'] . '.d';
+        if (is_dir($snippetsDir)) {
+            $snippets = glob($snippetsDir . '/*.php');
+            if ($snippets !== false) {
+                sort($snippets);  // Load in alphabetical order
+                $files = array_merge($files, $snippets);
+            }
+        }
+
+        // 4. Local override
+        $localFile = $confDir . $pathInfo['filename'] . '.local.' . $pathInfo['extension'];
+        $files[] = $localFile;
+
+        // Load files
+        $backends = [];
+
+        foreach ($files as $filePath) {
+            if (file_exists($filePath)) {
+                // Include file in isolated scope
+                $loadedBackends = $this->includeFile($filePath);
+
+                // Merge backends array
+                $backends = array_replace_recursive($backends, $loadedBackends);
+            }
+        }
+
+        // 5. VHost override (via Vhost object)
+        if ($this->vhost->isAvailable()) {
+            $vhostFilename = $this->vhost->getVhostFilename($file);
+            if ($vhostFilename) {
+                $vhostFile = $confDir . $vhostFilename;
+                if (file_exists($vhostFile)) {
+                    $loadedBackends = $this->includeFile($vhostFile);
+                    $backends = array_replace_recursive($backends, $loadedBackends);
+                }
+            }
+        }
+
+        return $backends;
+    }
+
+    /**
+     * Include PHP file in isolated scope and extract $backends variable
+     *
+     * @param string $file File path
+     * @return array Extracted backends array
+     */
+    private function includeFile(string $file): array
+    {
+        // Define variables that config files expect
+        $backends = [];
+
+        // Include file
+        include $file;
+
+        // Return $backends variable
+        return $backends;
+    }
+}

src/Config/BackendState.php

@@ -0,0 +1,90 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright 2026 The Horde Project (http://www.horde.org/)
+ *
+ * See the enclosed file LICENSE for license information (LGPL). If you
+ * did not receive this file, see http://www.horde.org/licenses/lgpl21.
+ *
+ * @category  Horde
+ * @copyright 2026 The Horde Project
+ * @license   http://www.horde.org/licenses/lgpl21 LGPL 2.1
+ * @package   Core
+ */
+
+namespace Horde\Core\Config;
+
+/**
+ * Backend configuration state
+ *
+ * Immutable state object holding backend definitions loaded from backends.php
+ *
+ * @category  Horde
+ * @copyright 2026 The Horde Project
+ * @license   http://www.horde.org/licenses/lgpl21 LGPL 2.1
+ * @package   Core
+ */
+class BackendState
+{
+    /**
+     * Constructor
+     *
+     * @param array $backends Merged backend definitions
+     */
+    public function __construct(
+        private array $backends
+    ) {
+    }
+
+    /**
+     * Get specific backend definition
+     *
+     * @param string $name Backend name ('hordesql', 'ldap', etc.)
+     * @return array|null Backend config or null if not found
+     */
+    public function getBackend(string $name): ?array
+    {
+        return $this->backends[$name] ?? null;
+    }
+
+    /**
+     * List all backends
+     *
+     * @param bool $includeDisabled Include disabled backends (default: false)
+     * @return array Backend definitions keyed by name
+     */
+    public function listBackends(bool $includeDisabled = false): array
+    {
+        if ($includeDisabled) {
+            return $this->backends;
+        }
+
+        return array_filter(
+            $this->backends,
+            fn ($backend) => empty($backend['disabled'])
+        );
+    }
+
+    /**
+     * Check if backend exists
+     *
+     * @param string $name Backend name
+     * @return bool True if backend exists (regardless of disabled status)
+     */
+    public function hasBackend(string $name): bool
+    {
+        return isset($this->backends[$name]);
+    }
+
+    /**
+     * Get all backends as array (for legacy compatibility)
+     *
+     * @return array Raw backends array
+     */
+    public function toArray(): array
+    {
+        return $this->backends;
+    }
+}