Implement ticket links and blocker state

app/Models/TicketLinkType.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Models;
+
+use Database\Factories\TicketLinkTypeFactory;
+use Illuminate\Database\Eloquent\Attributes\Fillable;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+#[Fillable(['label', 'position', 'project_id'])]
+class TicketLinkType extends Model
+{
+    /** @use HasFactory<TicketLinkTypeFactory> */
+    use HasFactory;
+
+    public function project(): BelongsTo
+    {
+        return $this->belongsTo(Project::class);
+    }
+
+    public function ticketLinks(): HasMany
+    {
+        return $this->hasMany(TicketLink::class)
+            ->orderBy('id');
+    }
+}