feat(cnn_v3): wire trained weights into CNNv3Effect + add timeline test sequence

- CNNv3Effect constructor loads ASSET_WEIGHTS_CNN_V3 via GetAsset on startup
- seq_compiler.py: CLASS_TO_HEADER supports full #include paths for cnn_v3/ classes
- timeline.seq: add cnn_v3_test sequence at 48s (GBufferEffect → CNNv3Effect)
- test_cnn_v3_parity: zero_weights test now explicitly uploads zeros to override asset

handoff(Gemini): CNNv3Effect ready; export weights to workspaces/main/weights/ and seek to 48s to test

6 files changed, 36 insertions, 3 deletions

diff --git a/cnn_v3/src/cnn_v3_effect.cc b/cnn_v3/src/cnn_v3_effect.cc
index 759e7ef..4aa2c25 100644
--- a/cnn_v3/src/cnn_v3_effect.cc
+++ b/cnn_v3/src/cnn_v3_effect.cc
@@ -2,8 +2,16 @@
 // See cnn_v3/docs/CNN_V3.md for architecture, HOWTO.md §7 for shader details.
 
 #include "cnn_v3_effect.h"
+
+#if defined(USE_TEST_ASSETS)
+#include "test_assets.h"
+#else
+#include "generated/assets.h"
+#endif
+
 #include "gpu/gpu.h"
 #include "gpu/shader_composer.h"
+#include "util/asset_manager.h"
 #include "util/fatal_error.h"
 #include <cstdint>
 #include <cstring>
@@ -180,6 +188,14 @@ CNNv3Effect::CNNv3Effect(const GpuContext& ctx,
   for (int i = 0; i < 4; ++i) { dec0_params_.gamma[i] = 1.0f; }
 
   create_pipelines();
+
+  // Load trained weights from asset system (zero-initialized if absent).
+  size_t weights_size = 0;
+  const void* weights_data =
+      GetAsset(AssetId::ASSET_WEIGHTS_CNN_V3, &weights_size);
+  if (weights_data && weights_size == kWeightsBufBytes) {
+    upload_weights(ctx_.queue, weights_data, (uint32_t)weights_size);
+  }
 }
 
 // ---------------------------------------------------------------------------
diff --git a/src/tests/gpu/test_cnn_v3_parity.cc b/src/tests/gpu/test_cnn_v3_parity.cc
index 4b41c94..15fe818 100644
--- a/src/tests/gpu/test_cnn_v3_parity.cc
+++ b/src/tests/gpu/test_cnn_v3_parity.cc
@@ -188,6 +188,12 @@ static std::vector<float> run_cnn_v3(WebGPUTestFixture& fixture,
 
   if (weights_u32) {
     effect.upload_weights(ctx.queue, weights_u32, weights_bytes);
+  } else {
+    // Explicitly zero weights to override any asset-loaded defaults.
+    // kWeightsBufBytes = ((1964+1)/2)*4 = 3928
+    const uint32_t zero_size = ((1964u + 1u) / 2u) * 4u;
+    std::vector<uint8_t> zeros(zero_size, 0);
+    effect.upload_weights(ctx.queue, zeros.data(), zero_size);
   }
 
   // Run 5 compute passes
diff --git a/tools/seq_compiler.py b/tools/seq_compiler.py
index dfd2ea4..fbd5c0d 100755
--- a/tools/seq_compiler.py
+++ b/tools/seq_compiler.py
@@ -391,14 +391,21 @@ def generate_cpp(seq: SequenceDecl, sorted_effects: List[EffectDecl],
     class_name += f'_{seq_index}_Sequence'
 
     # Generate includes
-    # Map class names that share a header file
+    # Map class names to header stems (default path: effects/<stem>_effect.h)
+    # Use a full #include string to override the path entirely.
     CLASS_TO_HEADER = {
-        'NtscYiq': 'ntsc',
+        'NtscYiq':       'ntsc',
+        'GBufferEffect': '#include "../../cnn_v3/src/gbuffer_effect.h"',
+        'CNNv3Effect':   '#include "../../cnn_v3/src/cnn_v3_effect.h"',
     }
     includes = set()
     for effect in seq.effects:
         if effect.class_name in CLASS_TO_HEADER:
-            header = CLASS_TO_HEADER[effect.class_name]
+            val = CLASS_TO_HEADER[effect.class_name]
+            if val.startswith('#include'):
+                includes.add(val)
+                continue
+            header = val
         else:
             # Convert ClassName to snake_case header
             header = re.sub('([A-Z])', r'_\1', effect.class_name).lower().lstrip('_')
diff --git a/workspaces/main/timeline.seq b/workspaces/main/timeline.seq
index ee7e1e7..1a9cad3 100644
--- a/workspaces/main/timeline.seq
+++ b/workspaces/main/timeline.seq
@@ -42,3 +42,7 @@ SEQUENCE 30.00 3 "complex_chain"
 SEQUENCE 40.00 0 "ntsc"
   EFFECT + Scene1 source -> temp1 0.00 8.00
   EFFECT + Ntsc temp1 -> sink 0.00 8.00
+
+SEQUENCE 48.00 0 "cnn_v3_test"
+  EFFECT + GBufferEffect source -> gbuf_feat0 gbuf_feat1 0.00 8.00
+  EFFECT + CNNv3Effect gbuf_feat0 gbuf_feat1 -> sink 0.00 8.00
diff --git a/workspaces/main/weights/cnn_v3_film_mlp.bin b/workspaces/main/weights/cnn_v3_film_mlp.bin
new file mode 100644
index 0000000..a49dcbe
--- /dev/null
+++ b/workspaces/main/weights/cnn_v3_film_mlp.bin
diff --git a/workspaces/main/weights/cnn_v3_weights.bin b/workspaces/main/weights/cnn_v3_weights.bin
new file mode 100644
index 0000000..7890fea
--- /dev/null
+++ b/workspaces/main/weights/cnn_v3_weights.bin