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/Models/Concerns/HasPublicationWindow.php

@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models\Concerns;
+
+use Illuminate\Database\Eloquent\Builder;
+
+/**
+ * A record that is only true between two dates.
+ *
+ * The window is enforced by each model's `published` scope, so nothing that
+ * reads public content has to remember it. What lives here are the questions
+ * the panel asks about that window — is this waiting for its date, has it
+ * already passed — because a panel that shows "Published" for something the
+ * site is not showing is lying to the person who wrote it.
+ */
+trait HasPublicationWindow
+{
+    /**
+     * Waiting for its date to arrive.
+     */
+    public function isScheduled(): bool
+    {
+        return $this->published_at !== null && $this->published_at->isFuture();
+    }
+
+    /**
+     * Past its end date, and therefore off the site.
+     */
+    public function hasExpired(): bool
+    {
+        return $this->unpublish_at !== null && $this->unpublish_at->isPast();
+    }
+
+    /**
+     * About to go, so it can be flagged before somebody notices it vanished.
+     */
+    public function expiresSoon(int $days = 7): bool
+    {
+        return $this->unpublish_at !== null
+            && $this->unpublish_at->isFuture()
+            && $this->unpublish_at->lt(now()->addDays($days));
+    }
+
+    /**
+     * @param  Builder<static>  $query
+     * @return Builder<static>
+     */
+    public function scopeScheduled(Builder $query): Builder
+    {
+        return $query->whereNotNull('published_at')->where('published_at', '>', now());
+    }
+
+    /**
+     * @param  Builder<static>  $query
+     * @return Builder<static>
+     */
+    public function scopeExpired(Builder $query): Builder
+    {
+        return $query->whereNotNull('unpublish_at')->where('unpublish_at', '<=', now());
+    }
+}