Support rendering web content in layers

[yorkie]

This PR supports rendering web content in layers by scrollable containers, this is required to achieve the complete overflow implementation.

[Copilot]

Pull Request Overview

This PR adds support for rendering web content in layers by introducing a new RenderLayer component and updating the rendering pipeline to support transparent materials. The changes enable proper rendering of scrollable containers with overflow handling by supporting both opaque and transparent render passes.

• Introduces RenderLayer component to support layered rendering
• Updates web content materials to use transparent rendering instead of opaque
• Removes render pass filtering to allow both opaque and transparent passes

Reviewed Changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
scene.hpp	Adds include for new RenderLayer header
scene.cpp	Registers RenderLayer component and adds it to entity creation
scene_renderer.cpp	Adds stencil buffer clearing before volume mask rendering
mesh_material.hpp	Adds transparency checks and render pass matching logic
web_content_instanced.cpp	Changes web content material from opaque to transparent
material_base.hpp	Adds constructor overload to specify opacity
client_renderer.hpp	Removes documentation comments
client_renderer.cpp	Removes render pass filtering and adds material pass matching

[Copilot]

The assertion duplicates the logic in the if-else conditions below. Consider removing the assertion or simplifying the function to avoid redundant checks.

Suggested change

assert(pass == RenderPass::kOpaques || pass == RenderPass::kTransparents);

[Copilot]

The final else clause will never execute due to the assertion above. If the assertion is removed, this should be unreachable code. Consider removing this clause or handling unexpected enum values appropriately.

Suggested change

	else if (pass == RenderPass::kTransparents)
	return isTransparent();
	else
	return false;
	else // pass == RenderPass::kTransparents
	return isTransparent();

[Copilot]

[nitpick] The comment explains why web content uses transparent material, but it would be helpful to explain the relationship to overflow implementation or layer rendering mentioned in the PR description.

Suggested change

	: Material(false) // Web content must use transparent material
	: Material(false) // Web content must use transparent material to ensure proper rendering of layers and handling of overflow. Transparent material allows blending and compositing of web content layers, which is essential for implementing overflow behavior and maintaining visual fidelity.

[Copilot]

Grammar error: 'does not for this render pass' should be 'does not match this render pass' or similar.

Suggested change

	// Skip rendering if the material does not for this render pass, such as the mesh is not opaque but the render pass
	// Skip rendering if the material does not match this render pass, such as when the mesh is not opaque but the render pass