fix(shaders): deduplicate VertexOutput/vs_main via render/fullscreen_uv_vs snippet

- Fix vs_main return type (VertexOutput, not vec4<f32>)
- Fix #include paths in passthrough, gaussian_blur, heptagon, combined_postprocess
- ShaderComposer: assert + suggest correct path on missing #include (non-STRIP_ALL)
- VerifyIncludes: upgrade WARNING to ERROR + assert, add "did you mean?" hint

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 1 insertions, 14 deletions

diff --git a/common/shaders/combined_postprocess.wgsl b/common/shaders/combined_postprocess.wgsl
index d56386e..bf43d6e 100644
--- a/common/shaders/combined_postprocess.wgsl
+++ b/common/shaders/combined_postprocess.wgsl
@@ -3,25 +3,12 @@
 
 #include "sequence_uniforms"
 #include "postprocess_inline"
+#include "render/fullscreen_uv_vs"  // <- VertexOutput + vs_main
 
 @group(0) @binding(0) var input_sampler: sampler;
 @group(0) @binding(1) var input_texture: texture_2d<f32>;
 @group(0) @binding(2) var<uniform> uniforms: UniformsSequenceParams;
 
-struct VertexOutput {
-    @builtin(position) position: vec4<f32>,
-    @location(0) uv: vec2<f32>,
-};
-
-@vertex fn vs_main(@builtin(vertex_index) vid: u32) -> VertexOutput {
-    var out: VertexOutput;
-    let x = f32((vid & 1u) << 1u);
-    let y = f32((vid & 2u));
-    out.position = vec4<f32>(x * 2.0 - 1.0, 1.0 - y * 2.0, 0.0, 1.0);
-    out.uv = vec2<f32>(x, y);
-    return out;
-}
-
 @fragment fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
     // Sample base color
     var color = textureSample(input_texture, input_sampler, in.uv);