Initial commit: Pireon Admin — headless admin panel and public API

Laravel 13 + Filament 5 admin panel and REST API for a non-profit developer
collective, backed by the Pireon OAuth identity server. The public site is a
separate, server-rendered application consuming /api/public/v1.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/Support/SiteUrls.php

@@ -0,0 +1,76 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Support;
+
+use Illuminate\Database\Eloquent\Model;
+
+/**
+ * Builds the public-site URLs and hreflang alternates for a translatable
+ * record.
+ *
+ * This lives in the API rather than the frontend for one reason: only the API
+ * knows that `/ca/projectes/el-meu-projecte` and `/proyectos/mi-proyecto` are
+ * the same record. Without it the frontend cannot emit correct `hreflang`
+ * tags, and search engines treat the three languages as duplicates.
+ */
+final class SiteUrls
+{
+    /**
+     * Every locale in which a record has a slug, mapped to its public path.
+     *
+     * @return array<string, string>
+     */
+    public static function alternates(Model $record, string $type, string $slugField = 'slug'): array
+    {
+        $alternates = [];
+
+        foreach (array_keys(config('locales.supported')) as $locale) {
+            $slug = $record->getTranslation($slugField, $locale, useFallbackLocale: false);
+
+            // A locale without its own slug has no URL of its own — emitting
+            // one would advertise a page that does not exist.
+            if (blank($slug)) {
+                continue;
+            }
+
+            $alternates[$locale] = self::path($type, $locale, (string) $slug);
+        }
+
+        return $alternates;
+    }
+
+    /**
+     * Absolute URLs for the same set, ready to drop into `<link hreflang>`.
+     *
+     * @return array<string, string>
+     */
+    public static function absoluteAlternates(Model $record, string $type, string $slugField = 'slug'): array
+    {
+        return array_map(
+            fn (string $path) => rtrim(config('site.url'), '/').$path,
+            self::alternates($record, $type, $slugField),
+        );
+    }
+
+    /**
+     * The path a record occupies on the public site, e.g. "/ca/projectes/foo".
+     */
+    public static function path(string $type, string $locale, string $slug): string
+    {
+        $segments = [];
+
+        if ($locale !== config('locales.default') || config('site.prefix_default_locale')) {
+            $segments[] = $locale;
+        }
+
+        if ($prefix = config("site.paths.{$type}.{$locale}")) {
+            $segments[] = $prefix;
+        }
+
+        $segments[] = $slug;
+
+        return '/'.implode('/', array_filter($segments, fn ($s) => $s !== ''));
+    }
+}