Add Campaigns module for grouping short links.

Let accounts organise links by promo or launch, attach or detach links, and view combined click totals from the sidebar.

app/Models/Campaign.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+class Campaign extends Model
+{
+    public const STATUS_DRAFT = 'draft';
+
+    public const STATUS_ACTIVE = 'active';
+
+    public const STATUS_ARCHIVED = 'archived';
+
+    public const STATUSES = [
+        self::STATUS_DRAFT => 'Draft',
+        self::STATUS_ACTIVE => 'Active',
+        self::STATUS_ARCHIVED => 'Archived',
+    ];
+
+    protected $fillable = [
+        'user_id',
+        'name',
+        'description',
+        'status',
+        'starts_at',
+        'ends_at',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'starts_at' => 'datetime',
+            'ends_at' => 'datetime',
+        ];
+    }
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function shortLinks(): HasMany
+    {
+        return $this->hasMany(ShortLink::class);
+    }
+
+    public function statusLabel(): string
+    {
+        return self::STATUSES[$this->status] ?? ucfirst((string) $this->status);
+    }
+
+    public function isLive(): bool
+    {
+        if ($this->status !== self::STATUS_ACTIVE) {
+            return false;
+        }
+
+        if ($this->starts_at && $this->starts_at->isFuture()) {
+            return false;
+        }
+
+        if ($this->ends_at && $this->ends_at->isPast()) {
+            return false;
+        }
+
+        return true;
+    }
+
+    public function totalClicks(): int
+    {
+        return (int) $this->shortLinks()->sum('clicks_total');
+    }
+
+    public function linksCount(): int
+    {
+        return (int) $this->shortLinks()->count();
+    }
+}