Fix Dutch model table names and seeder status values

- Add explicit $table property to all Eloquent models with Dutch names
- Fix pivot table names in belongsToMany relationships
- Fix seeder: use valid enum values for afhankelijkheden status

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/Models/Project.php

@@ -15,6 +15,8 @@ class Project extends Model
 {
     use SoftDeletes;
 
+    protected $table = 'projects';
+
     protected $fillable = [
         'speerpunt_id',
         'naam',
@@ -48,7 +50,7 @@ class Project extends Model
 
     public function teamleden(): BelongsToMany
     {
-        return $this->belongsToMany(User::class)
+        return $this->belongsToMany(User::class, 'project_user')
             ->withPivot('rol')
             ->withTimestamps()
             ->using(ProjectUser::class);