`SoftDeletes` methods (`onlyTrashed`, `withTrashed`) fail on base Builder instances

[alies-dev]

Problem

SoftDeletes trait declares @method static for withTrashed(), onlyTrashed(), and withoutTrashed(). These work for static model calls (Member::onlyTrashed()) via Psalm's pseudo_static_methods, but fail on builder instances:

User::query()
    ->whereHas('payment_method', fn(Builder $q) => $q->whereNull('deleted_at'))
    ->onlyTrashed() // ❌ UndefinedMagicMethod
    ->get();

At runtime, SoftDeletingScope registers these as Builder macros via Builder::macro(), so they work on any Builder instance. Psalm doesn't know about this.

Context

PR #632 fixed this for models with custom builders by detecting @method static annotations returning Builder<static> and registering them on the custom builder class. But for models using the base Builder (the common case), there's no equivalent handler.

Suggested fix

Register trait-declared builder methods (like SoftDeletes' withTrashed/onlyTrashed/withoutTrashed) on the base Builder class as well, not just custom builders. This could be done in BuilderScopeHandler or via a new handler registered for Builder::class that checks the model's pseudo_static_methods for builder-returning methods.

The tricky part is that Builder<TModel> is generic — the handler needs to resolve the model from the template parameter to know which trait methods are available.