Add Ladill Link URL shortener on ladl.link.

Management UI at link.ladill.com with GHS 0.05 per link wallet billing,
click analytics, and legacy fallback to ladill.com/q for QR ecosystem codes.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Models/LinkWallet.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+class LinkWallet extends Model
+{
+    public const STATUS_ACTIVE = 'active';
+
+    protected $fillable = [
+        'user_id',
+        'links_total',
+        'clicks_total',
+        'status',
+    ];
+
+    protected $casts = [
+        'links_total' => 'integer',
+        'clicks_total' => 'integer',
+    ];
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function transactions(): HasMany
+    {
+        return $this->hasMany(LinkTransaction::class);
+    }
+
+    public static function pricePerLink(): float
+    {
+        return (float) config('link.price_per_link_ghs', 0.05);
+    }
+}