add-shader

name	add-shader
description	Adds GLSL 450 vertex/fragment shaders to Spectra, SPIR-V compile at configure time, pipeline registration, and renderer draw integration. Use for new visual primitives, SDF line/marker shaders, or 3D lighting in src/gpu/shaders/.

Add Shader

1. src/gpu/shaders/<name>.vert and <name>.frag (#version 450)
2. cmake/CompileShaders.cmake — add to SHADER_SOURCES
3. src/render/vulkan/vk_pipeline.cpp — pipeline + PipelineConfig
4. src/render/renderer.cpp — draw method + push constants
5. Re-configure CMake (SPIR-V is configure-time, not build-only)

Conventions

• Push constants for MVP, color, per-draw uniforms
• SDF anti-aliasing in fragment shaders for 2D primitives
• 3D: enable depth test/write; see 3d-rendering

Validate: build-and-test, then graphical-change-workflow.