Bug Description

When emitting any quad with DEFAULT ambient occlusion from FabricBlockStateModel#emitQuads when rendering the breaking overlay, this causes a crash because NonTerrainBlockRenderContext.defaultLightMode is null.

The only place defaultLightMode is set for NonTerrainBlockRenderContext is in AbstractBlockRenderContext#bufferDefaultModel. The default implementation for FabricBlockStateModel#emitQuads calls FabricBlockModelPart#emitQuads for all block model parts parts which in turn ends up calling AbstractBlockRenderContext#bufferDefaultModel.
When emitting a quad directly from FabricBlockStateModel#emitQuads (with ambient occlusion set to default), AbstractBlockRenderContext#bufferDefaultModel is never called and thus AbstractBlockRenderContext.defaultLightMode is null. This then results in a crash when calling LightPipelineProvider#getLighter with a null argument.

Reproduction Steps

Create a BlockStateModel which overwrites FabricBlockStateModel#emitQuads to emit a quad:

public class DummyBlockStateModel implements BlockStateModel {
   
   ...
   
   @Override
   public void emitQuads(QuadEmitter emitter, BlockAndTintGetter blockView, BlockPos pos, BlockState state, RandomSource random, Predicate<@Nullable Direction> cullTest){
        emitter.emit();
   }
}

Overwrite the block model for cobblestone:

ModelLoadingPlugin.register(context -> {
    context.modifyBlockModelAfterBake().register(
        (model, modelContext) -> {
            if(modelContext.state().is(Blocks.COBBLESTONE))
                return new DummyBlockStateModel();
            return model;
        }
    );
});

Try to break a cobblestone block in survival such that it would show the block breaking overlay.
Observe that the game crashes.

Log File

latest.log

Crash Report

crash-2025-07-21_16.31.55-client.txt

I believe I'm getting the same issue.
Crash Logs: https://mclo.gs/VhymMgk