Update draft spec and READMEs to document accumulator non-revocation additions

Bumps PROTOCOL_ID to CREDKIT-PROOFS-V4, adds Section 7 (accumulator non-revocation), new wire format sections for accumulator params/updates/proofs, and expanded security/privacy considerations. Adds references for VB20, VB-ATTACK, KB21, ALLOSAUR, and CH09. Updates package tables to include @credkit/accumulator, test counts (371 → 459), and README prose across proofs, cryptosuite, and accumulator packages. Adds a .claude/launch.json dev configuration for the vgw-dmv app.

Author: tmarkovski

.claude/launch.json

@@ -0,0 +1,11 @@
+{
+  "version": "0.0.1",
+  "configurations": [
+    {
+      "name": "vgw-dmv",
+      "runtimeExecutable": "pnpm",
+      "runtimeArgs": ["--dir", "/Users/tm/git/tmarkovski/verygoodwallet", "--filter", "@vgw/dmv", "dev"],
+      "port": 5174
+    }
+  ]
+}

README.md

@@ -5,8 +5,9 @@ runtime.
 
 credkit combines BBS signatures, blind issuance, and composite zero-knowledge proofs so a holder
 can selectively disclose credential fields, prove that credentials share a holder-controlled
-secret, and prove facts about signed values without revealing the values themselves. The complete
-flow is packaged as JSON-LD Verifiable Credentials and Verifiable Presentations.
+secret, prove facts about signed values without revealing the values themselves, and prove that a
+credential has not been revoked without disclosing a stable status identifier. The complete flow
+is packaged as JSON-LD Verifiable Credentials and Verifiable Presentations.
 
 The construction is specified in the **[draft specification](https://tmarkovski.github.io/credkit/)**
 ([source](docs/draft-credkit-composite-proofs.md)).
@@ -28,32 +29,38 @@ The construction is specified in the **[draft specification](https://tmarkovski.
 - **Predicates over hidden values.** Range and arbitrary-set membership proofs are bound directly
   to signed numeric messages: prove a hidden birth date satisfies an age threshold, or a hidden
   state belongs to an allowed set, without revealing the value.
+- **Privacy-preserving revocation.** A holder proves membership in the issuer's current unrevoked
+  set without revealing the credential's revocation id. Issuance does not change the registry;
+  public deletion-only updates let every non-revoked holder refresh a witness offline.
 - **JSON-LD credentials and presentations.** Issue and verify W3C-shaped credentials, and present
-  one or more credentials under a single merged challenge.
+  one or more credentials—including verifier-required non-revocation gates—under a single merged
+  challenge.
 
-All predicate and linkage proofs are bound to the BBS proofs inside one Fiat-Shamir transcript,
-so a verifier checks a single presentation rather than loosely coupled sub-proofs.
+All predicate, non-revocation, and linkage proofs are bound to the BBS proofs inside one
+Fiat-Shamir transcript, so a verifier checks a single presentation rather than loosely coupled
+sub-proofs.
 
 ## Packages
 
 | Package | What it provides |
 |---|---|
 | `@credkit/bbs` | IETF BBS core, blind commitment and issuance, and DISCLOSE/HIDE proof modes. All 33 vendored fixtures pass byte-for-byte with the SHA-256 and SHAKE-256 ciphersuites. |
 | `@credkit/range` | CCS set-membership and range proofs over BLS12-381, exposed as split-phase protocols for composition under an external challenge. |
-| `@credkit/proofs` | Multi-statement BBS presentations, one merged Fiat-Shamir challenge, hidden-witness equality, range predicates, and set-membership predicates. |
-| `@credkit/cryptosuite` | JSON-LD credential issuance and verification, numeric claim encoding, selective disclosure, predicates, holder binding, and single- or multi-credential Verifiable Presentations. |
+| `@credkit/accumulator` | VB positive accumulator for additions-static, deletion-only revocation registries, public witness updates, and a split-phase zero-knowledge membership proof. |
+| `@credkit/proofs` | Multi-statement BBS presentations, one merged Fiat-Shamir challenge, hidden-witness equality, range and set-membership predicates, and accumulator non-revocation gates. |
+| `@credkit/cryptosuite` | JSON-LD credential issuance and verification, selective disclosure, predicates, holder binding, revocable credentials, and single- or multi-credential Verifiable Presentations. |
 
 ```text
 @credkit/cryptosuite       JSON-LD credentials and presentations
            |
 @credkit/proofs            composite transcript and witness binding
-       /       \
-@credkit/bbs   @credkit/range
- BBS + blind    hidden-value predicates
-   issuance
+      /         |          \
+@credkit/bbs  @credkit/range  @credkit/accumulator
+ BBS + blind   hidden-value     private non-revocation
+   issuance     predicates
 ```
 
-The suite has **371 passing tests** across the four packages and both ciphersuites.
+The suite has **459 passing tests** across all five packages and both ciphersuites.
 Golden-vector and negative tests pin the custom transcripts and wire formats; the BBS package
 also uses the vendored upstream fixtures.
 
@@ -66,9 +73,10 @@ The standards boundary is intentional:
   [`packages/bbs/package.json`](packages/bbs/package.json).
 - Numeric messages and the split-phase proof API are narrow implementation extensions used by
   the composite layer.
-- Composite presentations and predicates use credkit's own transcript and wire format. They are
-  described in the [draft specification](docs/draft-credkit-composite-proofs.md), but currently
-  have no independent implementation or external test vectors.
+- Composite presentations, predicates, and accumulator non-revocation proofs use credkit's own
+  transcript and wire format. They are described in the
+  [draft specification](docs/draft-credkit-composite-proofs.md), but currently have no independent
+  implementation or external test vectors.
 - The JSON-LD layer borrows the document-processing shape of `bbs-2023`, but uses distinct
   cryptosuite identifiers and proof envelopes. A credkit proof is deliberately not a
   `bbs-2023` proof.
@@ -105,8 +113,9 @@ import specifiers to the `.ts` files (a ~15-line resolve plugin in esbuild or Vi
 packages/
   bbs/           BBS signatures and blind issuance
   range/         CCS range and set-membership proofs
-  proofs/        composite presentations and predicate binding
-  cryptosuite/   JSON-LD VC and VP integration
+  accumulator/   revocation registry, witness updates, and membership proofs
+  proofs/        composite presentations, predicate binding, and non-revocation
+  cryptosuite/   JSON-LD VC, VP, and revocation integration
 docs/
   draft-credkit-composite-proofs.md   draft specification source
   draft-credkit-composite-proofs.html rendered draft