docs: consolidate and sync docs with current codebase state

- PROJECT_CONTEXT.md: fix effect count (12→18), shader count (27→37),
  update CNN v3 pipeline description, tighten Next Up section
- TODO.md: fix priority numbering, restore GPU PCM synthesis as pending,
  streamline CNN v3 section, consolidate Future items
- doc/SEQUENCE.md: effect count 12→18
- cnn_v3/README.md: phases 1–7→1–9, test count 36→38, add phases 8–9
- cnn_v3/docs/HOWTO.md: fix dataset layout blender/photos→full/simple,
  update test counts 36→38 throughout
- doc/COMPLETED.md: archive FFT/timing/OLA fixes, remove false GPU PCM claim
- src/audio/audio_engine.cc: fix step comment numbering (6→5)
- src/audio/synth.cc: remove stale fractional_pos tempo-scaling comment

handoff(Gemini): docs now accurate — 18 effects, 37 shaders, 38/38 tests,
GPU PCM synthesis back in TODO as pending, CNN v3 dataset layout corrected.

2 files changed, 9 insertions, 7 deletions

diff --git a/cnn_v3/README.md b/cnn_v3/README.md
index a844b1b..bd54e50 100644
--- a/cnn_v3/README.md
+++ b/cnn_v3/README.md
@@ -31,7 +31,7 @@ Add images directly to these directories and commit them.
 
 ## Status
 
-**Phases 1–7 complete.** 36/36 tests pass.
+**Phases 1–9 complete.** 38/38 tests pass. Training bugs fixed (2026-03-27).
 
 | Phase | Status |
 |-------|--------|
@@ -42,6 +42,8 @@ Add images directly to these directories and commit them.
 | 5 — Parity validation | ✅ max_err=4.88e-4 |
 | 6 — Training script | ✅ train_cnn_v3.py |
 | 7 — Validation tools | ✅ GBufViewEffect + web sample loader |
+| 8 — Architecture upgrade [8,16] | ✅ enc_channels=[8,16], 16ch split into lo/hi pairs |
+| 9 — Training bug fixes | ✅ dec0 ReLU removed, FiLM MLP loaded from .bin |
 
 See `cnn_v3/docs/HOWTO.md` for the practical playbook (§9 covers validation tools).
 See `cnn_v3/docs/CNN_V3.md` for full design.
diff --git a/cnn_v3/docs/HOWTO.md b/cnn_v3/docs/HOWTO.md
index 67f7931..e8fd0a5 100644
--- a/cnn_v3/docs/HOWTO.md
+++ b/cnn_v3/docs/HOWTO.md
@@ -235,7 +235,7 @@ channel-dropout training.
 python3 cnn_v3/training/pack_photo_sample.py \
     --photo  input/photo1.jpg \
     --target target/photo1_styled.png \
-    --output dataset/photos/sample_001/
+    --output dataset/simple/sample_001/
 ```
 
 `--target` is required and must be a stylized ground-truth image at the same
@@ -245,9 +245,9 @@ resolution as the photo. The script writes it as `target.png` in the sample dir.
 
 ```
 dataset/
-  blender/
+  full/       # Blender G-buffer samples (--input-mode full)
     sample_0001/  sample_0002/  ...
-  photos/
+  simple/     # Photo/stylized pairs (--input-mode simple)
     sample_001/   sample_002/   ...
 ```
 
@@ -399,14 +399,14 @@ Test vectors generated by `cnn_v3/training/gen_test_vectors.py` (PyTorch referen
 
 | Phase | Status | Notes |
 |-------|--------|-------|
-| 1 — G-buffer (raster + pack) | ✅ Done | Integrated, 36/36 tests pass |
+| 1 — G-buffer (raster + pack) | ✅ Done | Integrated, 38/38 tests pass |
 | 1 — G-buffer (SDF shadow pass) | ✅ Done | `gbuf_shadow.wgsl`, proxy-box SDF |
 | 2 — Training infrastructure | ✅ Done | blender_export.py, pack_*_sample.py |
 | 3 — WGSL U-Net shaders | ✅ Done | 5 compute shaders + cnn_v3/common snippet |
-| 4 — C++ CNNv3Effect | ✅ Done | FiLM uniform upload, 36/36 tests pass |
+| 4 — C++ CNNv3Effect | ✅ Done | FiLM uniform upload, 38/38 tests pass |
 | 5 — Parity validation | ✅ Done | test_cnn_v3_parity.cc, max_err=4.88e-4 |
 | 6 — FiLM MLP training | ✅ Done | train_cnn_v3.py + cnn_v3_utils.py written |
-| 7 — G-buffer visualizer (C++) | ✅ Done | GBufViewEffect, 36/36 tests pass |
+| 7 — G-buffer visualizer (C++) | ✅ Done | GBufViewEffect, 38/38 tests pass |
 | 8 — Architecture upgrade [8,16] | ✅ Done | enc_channels=[8,16], multi-scale loss, 16ch textures split into lo/hi pairs |
 | 7 — Sample loader (web tool) | ✅ Done | "Load sample directory" in cnn_v3/tools/ |
 | 9 — Training bug fixes | ✅ Done | dec0 ReLU removed (output unblocked); FiLM MLP loaded at runtime |