feat: announcement

app/Models/Announcement.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+class Announcement extends Model
+{
+    protected $fillable = [
+        'image_id', 'title', 'description', 'link', 'start_date', 'end_date',
+    ];
+
+    protected $casts = [
+        'start_date' => 'datetime',
+        'end_date' => 'datetime',
+    ];
+
+    public function image(): BelongsTo
+    {
+        return $this->belongsTo(Image::class);
+    }
+
+    // Currently within its [start_date, end_date] window (null bounds = open-ended).
+    public function scopeActive($query)
+    {
+        $now = now();
+
+        return $query
+            ->where(fn ($q) => $q->whereNull('start_date')->orWhere('start_date', '<=', $now))
+            ->where(fn ($q) => $q->whereNull('end_date')->orWhere('end_date', '>=', $now));
+    }
+}