LAB-1203: fold generate-bin-twin into upsert-by-name generate, sharing the envelope codec with wire-format-reference

.github/workflows/verify.yml

@@ -45,7 +45,9 @@ jobs:
           node tools/interop-crosscheck.mjs
 
       - name: Python-frame verify (stdlib only)
-        run: python3 tools/python-frame-reference.py verify
+        run: |
+          python3 tools/test_python_frame_reference.py
+          python3 tools/python-frame-reference.py verify
 
       - name: File-backend format verify (stdlib only)
         run: python3 tools/file-backend-reference.py

CHANGELOG.md

@@ -92,6 +92,42 @@ All notable changes to the CacheKit Protocol Specification.
 
 ### Test Vectors
 
+- `tools/python-frame-reference.py generate` now **upserts by vector name**
+  (LAB-1203): it rebuilds only the vectors the installed `cachekit` wheel can
+  reproduce and leaves every other committed vector byte-untouched, so dropping
+  a committed vector is structurally impossible — which deletes the LAB-903
+  drop-refusal guard and both wheel-direction refusals, and folds the
+  append-only `generate-bin-twin` mode into `generate` (a protocol 1.1 wheel
+  rebuilds the `_bin` twin, a legacy wheel the legacy original; whenever both
+  default-path vectors are present the pair is checked to differ only in
+  envelope encoding, and a partial fixture missing either twin skips that
+  check with a stderr note rather than aborting). That check is a stderr
+  **warning**, not a hard failure (fix-loop, 2026-09-19, adversarial finding):
+  the legacy wheel is gone from every installable release, so `legacy` can
+  never be regenerated — a `_require()` there would permanently deadlock
+  `generate` the first time the default write path legitimately changes for
+  reasons other than the encoding flip. A human reviews the reported diff and
+  decides whether it's a codec/wheel regression or a genuine protocol
+  evolution; `generate` itself cannot tell the two apart. Pinned by
+  `tools/test_python_frame_reference.py` (new; wired into `verify.yml`
+  alongside the frame reference verify step), which asserts the divergence
+  path warns and does not raise.
+  The ByteStorage envelope codec is no longer reimplemented there: encode/decode
+  come from `tools/wire-format-reference.py`, the one shared implementation of
+  the encoding these fixtures pin. Rewritten vectors carry per-vector
+  `generator` provenance (and the top-level provenance flips to an explicit
+  "mixed provenance" statement the first time a previously-unstamped vector is
+  rewritten); `test-vectors/python-frame.json` is byte-unchanged by this
+  refactor, and a no-op `generate` never rewrites the file. The stdlib `verify`
+  leg got strictly stronger (expert-panel findings): it now fully decodes each
+  `payload_envelope` via the shared codec (enforcing the protocol 1.1 flip
+  exclusions — checksum stays an array of 8 integers, format stays fixstr),
+  requires the envelope to re-encode byte-identically (pinning the canonical
+  rmp_serde shortest-form encoding, including the outer fixarray(4) marker),
+  and pins the declared `compressed_data_hex`/`checksum_hex`/`original_size`/
+  `format` fields against the actual envelope bytes; the generate-time twin
+  proof now compares frame prefixes at the byte level, not as parsed JSON.
+
 - 7 legacy/`bin` vector pairs in `test-vectors/wire-format.json` (append-only;
   legacy vectors are retained forever as legacy-read proof; fixture
   1.0.0 → 1.1.1). The original six `bin` twins were generated by the stdlib-only