docs: add current continuation brief

README.md

@@ -95,6 +95,7 @@ project workspace or development destination.
 
 ## Project map
 
+- [Current continuation brief](docs/CODEX_HANDOFF.md)
 - [Project charter](docs/project-charter.md)
 - [Product and research roadmap](docs/roadmap.md)
 - [MOPA workbench UX requirements](docs/design/mopa-workbench-ux.md)

docs/CODEX_HANDOFF.md

@@ -0,0 +1,60 @@
+# Codex continuation brief
+
+- Updated: 2026-10-21
+- Current focus: M1 build, packaging and no-device acceptance
+- Hardware access: prohibited
+- Automatic toolchain installation: prohibited
+
+## Verified checkpoint
+
+The public repository currently passes 83 unit tests and the public-repository
+guard. The offline Rayforge/MeerK40t evidence covers addon lifecycle, MOPA
+settings and units, layer and recipe semantics, JCZ record/list encoding,
+negative cases, cancellation/recovery and synthetic LightBurn imports.
+
+The repository now provides:
+
+- an on-demand source/build entry point that never installs the Windows
+  toolchain;
+- a non-executing verifier for externally produced Windows artifacts;
+- a checksummed acceptance-kit generator containing only allowlisted public
+  synthetic inputs;
+- a fail-closed manual desktop-acceptance report and validator.
+
+Run the ordinary checkpoint with the bundled Codex Python or another supported
+Python interpreter and a writable `TEMP`/`TMP`:
+
+```powershell
+python -m unittest discover -s tests -v
+python scripts/check_public_repo.py .
+```
+
+## External gates
+
+M1 is not complete. Do not describe the repository as a finished desktop
+application until both gates below have real evidence:
+
+1. A Windows artifact for the pinned Rayforge revision must be produced on a
+   reviewed build runner, verified without execution, and pass the manual
+   no-device desktop checklist.
+2. A known-working private JPT `.lbrn2` project must establish how project-level
+   frequency and `QPulseWidth` are serialized before those fields are mapped.
+
+Raw projects, screenshots containing identifiers, machine data and build
+binaries stay out of the public repository.
+
+## Suggested first task
+
+If a Windows artifact is available, keep the machine disconnected and run, in
+order:
+
+1. `scripts/verify_rayforge_windows_checkpoint.py`;
+2. `scripts/prepare_m1_acceptance_kit.py`;
+3. the manual checklist in
+   `docs/research/m1-no-device-acceptance.md`;
+4. `scripts/validate_m1_manual_acceptance.py`.
+
+If no artifact is available, do not install a build environment here. The next
+useful input is the private known-working `.lbrn2` collection. Until either
+external gate arrives, ADR 0002 remains Proposed and no controller backend,
+USB discovery, physical framing, galvo motion or laser output is authorized.