docs+feat(cnn_v3): compact context, re-enable shadow in GBufDeferredEffect

- TODO/PROJECT_CONTEXT updated to reflect operational pipeline state
- GBufDeferredEffect: shadow re-enabled (albedo * (ambient + diffuse * shadow))
  feat_tex1 binding restored for shadow channel debugging

handoff(Gemini): shadow pass live again — investigate why shadow looks broken.

1 files changed, 10 insertions, 24 deletions

diff --git a/TODO.md b/TODO.md
index 66cbe76..e855384 100644
--- a/TODO.md
+++ b/TODO.md
@@ -14,7 +14,7 @@ Procedural spectrogram tool: 50-100× compression (5 KB .spec → ~100 bytes C++
 
 ## Priority 2: Test Infrastructure Maintenance [ONGOING]
 
-**Status:** 35/35 tests passing
+**Status:** 38/38 tests passing
 
 **Outstanding TODOs:**
 
@@ -62,32 +62,18 @@ Ongoing shader code hygiene for granular, reusable snippets.
 
 ## CNN v3 — U-Net + FiLM [IN PROGRESS]
 
-U-Net architecture with FiLM conditioning. Runtime style control via beat/audio.
-Richer G-buffer input (normals, depth, material IDs). Per-pixel testability across
-PyTorch / HTML WebGPU / C++ WebGPU.
+**Design:** `cnn_v3/docs/CNN_V3.md` | All phases 1–7 complete. Runtime pipeline operational.
 
-**Design:** `cnn_v3/docs/CNN_V3.md`
+**Current pipeline:** `GBufferEffect` → `GBufDeferredEffect` → sink (debug view: albedo×diffuse)
 
-**Phases:**
-1. ✅ G-buffer: `GBufferEffect` integrated. SDF/shadow placeholder (shadow=1, transp=0).
-2. ✅ Training infrastructure: `blender_export.py`, `pack_blender_sample.py`, `pack_photo_sample.py`
-3. ✅ WGSL shaders: cnn_v3_common (snippet), enc0, enc1, bottleneck, dec1, dec0
-4. ✅ C++ `CNNv3Effect`: 5 compute passes, FiLM uniform upload, `set_film_params()` API
-   - Params alignment fix: WGSL `vec3u` align=16 → C++ structs 64/96 bytes
-   - Weight offsets as explicit formulas (e.g. `20*4*9+4`)
-   - FiLM γ/β: identity defaults; real values require trained MLP (see below)
-5. ✅ Parity validation: test vectors + `test_cnn_v3_parity.cc`. max_err=4.88e-4 (≤1/255).
-   - Key fix: intermediate nodes at fractional resolutions (W/2, W/4) via `NodeRegistry::default_width()/default_height()`
+**Active work:**
+- [ ] Fix/validate shadow pass (`gbuf_shadow.wgsl`) — currently disabled in deferred
+- [ ] Re-enable shadow in `GBufDeferredEffect` once validated
+- [ ] Run first real training pass — see `cnn_v3/docs/HOWTO.md` §3
 
-6. ✅ Training script: `train_cnn_v3.py` + `cnn_v3_utils.py` written
-   - ✅ `export_cnn_v3_weights.py` — convert trained `.pth` → `.bin` (f16)
-7. ✅ Validation tools:
-   - `GBufViewEffect` — C++ 4×5 channel grid (all 20 G-buffer channels)
-   - Web tool "Load sample directory" — G-buffer pack → CNN inference → PSNR
-   - See `cnn_v3/docs/HOWTO.md` §9
-
-**Next: run a real training pass**
-- See `cnn_v3/docs/HOWTO.md` §3 for training commands
+**Pending (lower priority):**
+- [ ] GBufferEffect: Pass 3 transparency (transp=0 placeholder)
+- [ ] GBufferEffect: `resize()` support
 
 ## Future: CNN v3 "2D Mode" (G-buffer-free)