docs(v4.0.0): record the three products and v4's acceptance criteria

Both ruled by Captain Bob, 2026-10-03.

Products (README.md, JUSTIFICATION.md section 15): Hosted StarForth F18
(native Linux, amd64/arm64/riscv64, on hardware); FPGA StarForth F18 (a
32-bit build loaded into the FPGA, the gateway and foundation); and
StarshipOS (bare metal, LithosAnanke on the v4 F18 engine). FORTH-79
recomposed on the F18 engine is stored as a capsule, as are the
StarshipOS portions; the tree will be reorganised around this.

Acceptance (JUSTIFICATION.md section 16, v4/README.md): v4 is equivalent
to v3 at any point in time -- same vocabularies, same behaviour, on the
F18-derived engine -- and every ISA, hosted and bare metal, must still
reach its ok prompt. `make -C v4 test` is a development check, not
acceptance. v4 had no acceptance criteria before this.

Documentation only; no code changed.

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

README.md

@@ -6,6 +6,25 @@
 
 ---
 
+## Products
+
+StarForth v4 moves the engine onto a 32-instruction core derived from Chuck Moore's F18
+(`docs/v4.0.0/`). With it, this repository carries three products, not one:
+
+| Product | What it is |
+|---|---|
+| **Hosted StarForth F18** | The v4 engine as a native Linux build, for amd64, arm64 and riscv64, on real hardware. |
+| **FPGA StarForth F18** | A 32-bit build of the same engine loaded into the FPGA. It is the gateway to the rest: the foundation everything else is built up from. |
+| **StarshipOS** | The bare-metal product: LithosAnanke running the v4 F18 engine. |
+
+FORTH-79 is recomposed on the F18 engine and stored as a capsule; the StarshipOS-specific
+vocabulary gets the same treatment. The source tree will be reorganised around this split.
+
+v3 remains the reference system until v4 meets its acceptance criteria
+(`docs/v4.0.0/JUSTIFICATION.md` §16). Everything below describes v3 as it stands today.
+
+---
+
 ## Status — M7.1 (Capsule System · Multi-VM Fleet)
 
 | Milestone | | Status |

docs/v4.0.0/JUSTIFICATION.md

@@ -224,3 +224,34 @@ LithosAnanke filing is a question for counsel.
 - K≡1.0 holds on the golden model at both widths, on all three host ISAs.
 - A hosted mesh runs the Tripod roles as nodes, with Hermes as the network.
 - Verilator co-simulation of one node matches the golden model instruction for instruction.
+
+## 15. Products
+
+Ruled by Captain Bob, 2026-10-03. v4 turns one project into three products built on the same engine:
+
+1. **Hosted StarForth F18.** The v4 engine as a native Linux build for amd64, arm64 and riscv64, on
+   real hardware.
+2. **FPGA StarForth F18.** A 32-bit build of the engine loaded into the FPGA. This is the gateway into
+   building the whole system, and its foundation.
+3. **StarshipOS.** The bare-metal product: LithosAnanke running the v4 F18 engine.
+
+The FORTH-79 vocabulary, recomposed on the F18 engine (`DECOMPOSITION.md`), is stored as a capsule. The
+StarshipOS-specific portions are recomposed and stored as capsules in the same way. The source tree
+will be reorganised around this split.
+
+## 16. Acceptance criteria
+
+Ruled by Captain Bob, 2026-10-03. Until then v4 had none: this document and `v4/README.md` named a
+POST suite and K≡1.0 on three host ISAs, neither of which exists yet, so nothing could be called
+accepted.
+
+- **v4 is equivalent to v3 at any point in time.** It must provide the same vocabularies and behave
+  the same way. The only difference is the machine underneath: the F18-derived engine instead of the
+  original StarForth VM.
+- **Every ISA, hosted and bare metal, must still reach its `ok` prompt.** That is amd64, aarch64 and
+  riscv64, as a hosted build and as a bare-metal boot.
+
+The existing acceptance tests keep their force and their rules: the three-architecture QEMU boot for
+anything bare metal (`.claude/CLAUDE.md`), and the hosted three-architecture test
+(`docs/lithosananke/hosted-acceptance-test/README.md`). Passing `make -C v4 test` is a development
+check on the golden model, not acceptance.

v4/README.md

@@ -8,6 +8,11 @@ The first deliverable is the hosted C99 golden model (`JUSTIFICATION.md` §10,
 step 1). It must pass POST and hold K≡1.0 with 32- and 64-bit cells on all
 three host ISAs.
 
+Acceptance (`JUSTIFICATION.md` §16): v4 must be equivalent to v3 at any point
+in time, with the same vocabularies and behaviour, on the F18-derived engine;
+and every ISA, hosted and bare metal, must still reach its `ok` prompt.
+`make -C v4 test` passing is a development check, not acceptance.
+
 What exists so far is the single node: registers, circular stacks, memory, all
 32 opcodes, and per-opcode and per-call-target heat. `make -C v4 test` builds
 and runs the tests at both cell widths; `make -C v4 sanitize` repeats them