misterneo has created Issue #3541: has() / whereHas() fails when custom relationship keys are numeric strings in laravel-mongodb. This Jira ticket was filed by GromNaN

Issue Text:

1. `has()` / `whereHas()` fails when custom relationship keys are numeric strings

1. 1. Environment

• Laravel: 13.7.0
• mongodb/laravel-mongodb: 5.7.1
• mongodb/mongodb: 2.2.0

1. 1. Description

`has()` and `whereHas()` appear to fail when a relationship uses custom string keys whose values are *numeric strings* (e.g. `"1"`, `"2"`).

The relationship itself works correctly, but relationship existence queries (`has`, `whereHas`) return no results.

Using non-numeric strings (e.g. `"item-1"`) works as expected.

1. 1. Reproduction

Models

```php
class ParentModel extends Model
{
public function children()

{ return $this->hasMany(ChildModel::class, 'parent_key', 'custom_key'); }

}

class ChildModel extends Model
{
public function parent()

{ return $this->belongsTo(ParentModel::class, 'parent_key', 'custom_key'); }

}
```

Documents

*parents*

```json
{
"custom_key": "1"
}
```

*children*

```json
{
"parent_key": "1"
}
```

Working

```php
ParentModel::first()->children;
ParentModel::first()>children()>count();
ChildModel::where('parent_key', '1')->exists();
```

All of the above return the expected results.

Failing

```php
ParentModel::has('children')->get();
ParentModel::whereHas('children')->get();
```

These return an empty collection.

1. 1. Query log

The generated query contains BSON integers instead of strings:

```json
{
"custom_key": {
"$in": [

{ "$numberInt": "1" }

]
}
}
```

However, the stored values are BSON strings:

```json
{
"custom_key": "1"
}
```

Since MongoDB performs strict type matching, the query returns no results.

1. 1. Additional observation

If the values are changed from numeric strings to non-numeric strings, for example:

```json
{
"custom_key": "item-1"
}
```

and

```json
{
"parent_key": "item-1"
}
```

then `has()` and `whereHas()` work correctly.

This suggests that somewhere during the relationship existence query, numeric strings are being coerced into integers before the `$in` query is constructed.