fix: Register cnn_conv1x1 snippet and add verification

- Add cnn_conv1x1 to shader composer registration
- Add VerifyIncludes() to detect missing snippet registrations
- STRIP_ALL-protected verification warns about unregistered includes
- Fixes cnn_test runtime failure loading cnn_layer.wgsl

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

4 files changed, 136 insertions, 0 deletions

diff --git a/src/gpu/effects/shader_composer.cc b/src/gpu/effects/shader_composer.cc
index b746f8b..fe3ad74 100644
--- a/src/gpu/effects/shader_composer.cc
+++ b/src/gpu/effects/shader_composer.cc
@@ -86,3 +86,31 @@ ShaderComposer::Compose(const std::vector<std::string>& dependencies,
 
   return ss.str();
 }
+
+void ShaderComposer::VerifyIncludes() const {
+#if !defined(STRIP_ALL)
+  std::set<std::string> missing;
+  for (const auto& [name, code] : snippets_) {
+    std::istringstream stream(code);
+    std::string line;
+    while (std::getline(stream, line)) {
+      if (line.compare(0, 9, "#include ") == 0) {
+        size_t start = line.find('"');
+        size_t end = line.find('"', start + 1);
+        if (start != std::string::npos && end != std::string::npos) {
+          std::string included = line.substr(start + 1, end - start - 1);
+          if (snippets_.find(included) == snippets_.end()) {
+            missing.insert(included);
+          }
+        }
+      }
+    }
+  }
+  if (!missing.empty()) {
+    fprintf(stderr, "WARNING: Unregistered shader snippets:\n");
+    for (const auto& name : missing) {
+      fprintf(stderr, "  - %s\n", name.c_str());
+    }
+  }
+#endif
+}
diff --git a/src/gpu/effects/shader_composer.h b/src/gpu/effects/shader_composer.h
index 9eb43f4..d0972f2 100644
--- a/src/gpu/effects/shader_composer.h
+++ b/src/gpu/effects/shader_composer.h
@@ -24,6 +24,9 @@ class ShaderComposer {
                       const std::string& main_code,
                       const CompositionMap& substitutions = {});
 
+  // Verify all #include directives reference registered snippets
+  void VerifyIncludes() const;
+
  private:
   ShaderComposer() = default;
 
diff --git a/src/gpu/effects/shaders.cc b/src/gpu/effects/shaders.cc
index 5f78298..d79f3d3 100644
--- a/src/gpu/effects/shaders.cc
+++ b/src/gpu/effects/shaders.cc
@@ -53,11 +53,16 @@ void InitShaderComposer() {
   register_if_exists("ray_triangle", AssetId::ASSET_SHADER_RAY_TRIANGLE);
 
   register_if_exists("cnn_activation", AssetId::ASSET_SHADER_CNN_ACTIVATION);
+  register_if_exists("cnn_conv1x1", AssetId::ASSET_SHADER_CNN_CONV1X1);
   register_if_exists("cnn_conv3x3", AssetId::ASSET_SHADER_CNN_CONV3X3);
   register_if_exists("cnn_conv5x5", AssetId::ASSET_SHADER_CNN_CONV5X5);
   register_if_exists("cnn_conv7x7", AssetId::ASSET_SHADER_CNN_CONV7X7);
   register_if_exists("cnn_weights_generated",
                      AssetId::ASSET_SHADER_CNN_WEIGHTS);
+
+#if !defined(STRIP_ALL)
+  sc.VerifyIncludes();
+#endif
 }
 
 // Helper to get asset string or empty string
diff --git a/workspaces/main/shaders/cnn/cnn_conv1x1.wgsl b/workspaces/main/shaders/cnn/cnn_conv1x1.wgsl
new file mode 100644
index 0000000..d468182
--- /dev/null
+++ b/workspaces/main/shaders/cnn/cnn_conv1x1.wgsl
@@ -0,0 +1,100 @@
+// 1x1 convolution (vec4-optimized)
+
+// Inner layers: 7→4 channels (vec4-optimized)
+// Assumes 'tex' is already normalized to [-1,1]
+fn cnn_conv1x1_7to4(
+  tex: texture_2d<f32>,
+  samp: sampler,
+  uv: vec2<f32>,
+  resolution: vec2<f32>,
+  gray: f32,
+  weights: array<vec4<f32>, 8>
+) -> vec4<f32> {
+  let step = 1.0 / resolution;
+  let uv_norm = (uv - 0.5) * 2.0;
+
+  var sum = vec4<f32>(0.0);
+  var pos = 0;
+
+  for (var dy = -0; dy <= 0; dy++) {
+    for (var dx = -0; dx <= 0; dx++) {
+      let offset = vec2<f32>(f32(dx), f32(dy)) * step;
+      let rgbd = textureSample(tex, samp, uv + offset);
+      let in1 = vec4<f32>(uv_norm, gray, 1.0);
+
+      sum.r += dot(weights[pos+0], rgbd) + dot(weights[pos+1], in1);
+      sum.g += dot(weights[pos+2], rgbd) + dot(weights[pos+3], in1);
+      sum.b += dot(weights[pos+4], rgbd) + dot(weights[pos+5], in1);
+      sum.a += dot(weights[pos+6], rgbd) + dot(weights[pos+7], in1);
+      pos += 8;
+    }
+  }
+
+  return sum;
+}
+
+// Source layer: 7→4 channels (vec4-optimized)
+// Normalizes [0,1] input to [-1,1] internally
+fn cnn_conv1x1_7to4_src(
+  tex: texture_2d<f32>,
+  samp: sampler,
+  uv: vec2<f32>,
+  resolution: vec2<f32>,
+  weights: array<vec4<f32>, 8>
+) -> vec4<f32> {
+  let step = 1.0 / resolution;
+
+  let original = (textureSample(tex, samp, uv) - 0.5) * 2.0;
+  let gray = dot(original.rgb, vec3<f32>(0.2126, 0.7152, 0.0722));
+  let uv_norm = (uv - 0.5) * 2.0;
+  let in1 = vec4<f32>(uv_norm, gray, 1.0);
+
+  var sum = vec4<f32>(0.0);
+  var pos = 0;
+
+  for (var dy = -0; dy <= 0; dy++) {
+    for (var dx = -0; dx <= 0; dx++) {
+      let offset = vec2<f32>(f32(dx), f32(dy)) * step;
+      let rgbd = (textureSample(tex, samp, uv + offset) - 0.5) * 2.0;
+
+      sum.r += dot(weights[pos+0], rgbd) + dot(weights[pos+1], in1);
+      sum.g += dot(weights[pos+2], rgbd) + dot(weights[pos+3], in1);
+      sum.b += dot(weights[pos+4], rgbd) + dot(weights[pos+5], in1);
+      sum.a += dot(weights[pos+6], rgbd) + dot(weights[pos+7], in1);
+      pos += 8;
+    }
+  }
+
+  return sum;
+}
+
+// Final layer: 7→1 channel (vec4-optimized)
+// Assumes 'tex' is already normalized to [-1,1]
+// Returns raw sum (activation applied at call site)
+fn cnn_conv1x1_7to1(
+  tex: texture_2d<f32>,
+  samp: sampler,
+  uv: vec2<f32>,
+  resolution: vec2<f32>,
+  gray: f32,
+  weights: array<vec4<f32>, 2>
+) -> f32 {
+  let step = 1.0 / resolution;
+  let uv_norm = (uv - 0.5) * 2.0;
+  let in1 = vec4<f32>(uv_norm, gray, 1.0);
+
+  var sum = 0.0;
+  var pos = 0;
+
+  for (var dy = -0; dy <= 0; dy++) {
+    for (var dx = -0; dx <= 0; dx++) {
+      let offset = vec2<f32>(f32(dx), f32(dy)) * step;
+      let rgbd = textureSample(tex, samp, uv + offset);
+
+      sum += dot(weights[pos], rgbd) + dot(weights[pos+1], in1);
+      pos += 2;
+    }
+  }
+
+  return sum;
+}