Record what the Transformers.js 4.3.2 upgrade changes on the WebGPU side and what needs a browser check

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/Decisions.md

@@ -1252,3 +1252,43 @@ pipeline's wav2vec2/CTC path) plus `ParakeetFeatureExtractor`. There is no
 TDT/RNN-T (transducer) decoder or joint-network loop anywhere in the
 package, so **Parakeet TDT 0.6B v3 is not supported natively**; per the
 spec, that path uses `parakeet.js`.
+
+## D-WS1d — WebGPU-side effects of the 4.3.2 upgrade: inspected, not measured (needs the owner's browser check)
+**Status:** Open — inspection only (2026-10-29)
+This machine has no GPU and no browser WebGPU, so D-022, D-025 and D-026
+cannot be re-measured here. What the upgrade changes on that side, from the
+4.3.0–4.3.2 release notes and a 4.2.0↔4.3.2 source diff:
+- **onnxruntime-web 1.26.0-dev.20260416 → 1.31.0-dev.20260914.** Five minor
+  versions of WebGPU EP work land at once. The WebGPU bundle still uses the
+  same `ort-wasm-simd-threaded.asyncify` binary pair (now 26.9 MB, was
+  23.6 MB — a one-time re-download, evicted correctly because the SW cache
+  version hashes the worker bundle, which embeds the ort version). The JS
+  layer still has no Firefox/Gecko or Safari special-casing, and still
+  checks `shader-f16` / `isFallbackAdapter` as before.
+- **Safari 26+ WebGPU (Transformers.js 4.3.0, PR 1700).** The upstream change
+  only alters which binary Transformers.js picks for its jsDelivr default
+  (`IS_SAFARI` → `IS_SAFARI_BELOW_26`). This app overrides `wasmPaths` with
+  `./ort/`, so it never used that default; whether WebGPU is attempted on
+  Safari is decided by the worker's own probe (`navigator.gpu`, D-017/D-025),
+  unchanged.
+- **Whisper / ASR pipeline / streamers:** no functional change (comment
+  edits, `processor.batch_decode` → `tokenizer.batch_decode` on a
+  non-Whisper path, one `transpose` → `permute` rename). "Fix Whisper
+  progress callbacks" and "fix duplicate model file downloads when
+  `progress_callback` is active" (4.3.0) are in the file-loading path:
+  download progress may look different, and a duplicate fetch is avoided.
+- **Session/dtype selection (`session.js`, `dtypes.js`):** unchanged apart
+  from no longer exporting two constants.
+**Needs the owner's browser check** (decisions stay as they are until then):
+1. **Large v3 Turbo on WebGPU (the owner's setup):** load and transcribe
+   `tests/audio_files/en_aiproblem.m4a`; compare wall-clock with the 4.2.0
+   build and confirm the text is sane (fp16 encoder + q4 decoder, D-022
+   scope note).
+2. **D-026:** Firefox with Backend = WebGPU explicitly selected — still far
+   slower than WASM? If it is now at parity, drop the Firefox UA check.
+3. **D-022:** medium stays q4 on WebGPU/WebNN. A retest of the fp16
+   conversions is only worth doing if the owner wants medium faster on GPU.
+4. **D-025:** Firefox "auto" lands on multithreaded WASM (footer shows
+   "WASM (on-device, N threads)" with N > 1).
+5. **Safari 26 (macOS/iOS):** what the footer reports for "auto"; if WebGPU,
+   check speed and output.

docs/plans/001-1-transformers-upgrade.md

@@ -109,9 +109,9 @@ onnxruntime-node 1.30.0), bun:test.
 
 ### Task 4: WebGPU-affecting changes (D-022, D-025/D-026) — inspection only
 
-- [ ] **Step 1:** Read 4.3.0/4.3.1/4.3.2 release notes and diff 4.2.0↔4.3.2 `src/` for
+- [x] **Step 1:** Read 4.3.0/4.3.1/4.3.2 release notes and diff 4.2.0↔4.3.2 `src/` for
   WebGPU/fp16/Firefox/Safari changes; check ort-web 1.31 dist for Gecko/fp16 handling.
-- [ ] **Step 2:** `D-WS1d` listing each item as "needs owner's browser check" with what to try
+- [x] **Step 2:** `D-WS1d` listing each item as "needs owner's browser check" with what to try
   (explicit WebGPU on Firefox for D-026; medium fp16 for D-022; Safari 26 WebGPU). No code change.
   Commit.