archive(cnn): move CNN v1 to cnn_v1/ subdirectory

Consolidate CNN v1 (CNNEffect) into dedicated directory:
- C++ effect: src/effects → cnn_v1/src/
- Shaders: workspaces/main/shaders/cnn → cnn_v1/shaders/
- Training: training/train_cnn.py → cnn_v1/training/
- Docs: doc/CNN*.md → cnn_v1/docs/

Updated all references:
- CMake source list
- C++ includes (relative paths: ../../cnn_v1/src/)
- Asset paths (../../cnn_v1/shaders/)
- Documentation cross-references

CNN v1 remains active in timeline. For new work, use CNN v2 with
enhanced features (7D static, storage buffer, sigmoid activation).

Tests: 34/34 passing (100%)

1 files changed, 0 insertions, 53 deletions

diff --git a/src/effects/cnn_effect.h b/src/effects/cnn_effect.h
deleted file mode 100644
index cdcd656..0000000
--- a/src/effects/cnn_effect.h
+++ /dev/null
@@ -1,53 +0,0 @@
-// CNN post-processing effect header
-// Multi-layer neural network stylization
-
-#pragma once
-#include "gpu/effect.h"
-#include "gpu/uniform_helper.h"
-
-struct CNNLayerParams {
-  int layer_index;
-  float blend_amount; // Blend: mix(input, output, blend_amount)
-  float _pad[2];
-};
-static_assert(sizeof(CNNLayerParams) == 16);
-
-struct CNNEffectParams {
-  int layer_index = 0;       // Which layer to render (0-based)
-  int total_layers = 1;      // Total number of layers in the CNN
-  float blend_amount = 1.0f; // Final blend with original input
-};
-
-class CNNEffect : public PostProcessEffect {
- public:
-  explicit CNNEffect(const GpuContext& ctx);
-  explicit CNNEffect(const GpuContext& ctx, const CNNEffectParams& params);
-
-  void init(MainSequence* demo) override;
-  void resize(int width, int height) override;
-  void render(WGPURenderPassEncoder pass,
-              const CommonPostProcessUniforms& uniforms) override;
-  void update_bind_group(WGPUTextureView input_view) override;
-
-  // Layer 0 needs framebuffer capture for original input
-  bool needs_framebuffer_capture() const override {
-    return layer_index_ == 0;
-  }
-
-  void set_beat_modulation(bool enabled, float scale = 1.0f) {
-    beat_modulated_ = enabled;
-    beat_scale_ = scale;
-  }
-
- private:
-  int layer_index_;
-  int total_layers_;
-  float blend_amount_;
-  bool beat_modulated_ = false;
-  float beat_scale_ = 1.0f;
-  WGPUTextureView input_view_;
-  WGPUTextureView original_view_;
-  UniformBuffer<CNNLayerParams> params_buffer_;
-  WGPUBindGroup bind_group_;
-  MainSequence* demo_ = nullptr;
-};