fed-sx-m1: Step 5a — pure-functional registry (new/register/lookup/list) + 14 tests

plans/fed-sx-milestone-1.md

@@ -337,6 +337,12 @@ created with a known stable CID.
 
 ## Step 5 — Registry mechanism + bootstrap dispatch
 
+**Sub-deliverables:**
+- [x] **5a** — Pure-functional `next/kernel/registry.erl`: `new/0`, `kinds/0`, `register/4`, `lookup/3`, `list/2`. State is a property list keyed by kind atom; per-kind storage is a property list of `{Name, Entry}`. Unknown kinds rejected with `{error, unknown_kind}`. `next/tests/registry_pure.sh` (14 cases).
+- [ ] **5b** — gen_server wrapper around the pure registry: `start_link/0`, registered name `registry`, the pure API delegated through `gen_server:call`.
+- [ ] **5c** — `bootstrap:load_genesis/1` (Step 4e) populates the registry from `read_genesis` output. Dispatches by section atom → kind.
+- [ ] **5d** — define-registry projection fold integration: incoming `Create{Define*}` activities are routed through the projection scheduler (Step 7) and update the registry.
+
 **Deliverables:**
 
 Registries are gen_servers, one per kind, each holding the active version map:
@@ -955,6 +961,7 @@ A few things still under-specified; resolve as work begins.
 Newest first. One line per sub-deliverable commit. Erlang conformance gate
 (`bash lib/erlang/conformance.sh`) must remain 729/729 on every entry.
 
+- **2026-05-28** — Step 5a: `next/kernel/registry.erl` — pure-functional registry. State is `[{Kind, [{Name, Entry}, ...]}, ...]` keyed by the same seven section atoms as Step 4c (activity_types, object_types, projections, validators, codecs, sig_suites, audience). API: `new/0`, `kinds/0`, `register/4`, `lookup/3`, `list/2`. Unknown kinds rejected with `{error, unknown_kind}`; missing names return `not_found`; re-registering the same name overrides without growing the list. `next/tests/registry_pure.sh` 14/14. Step 5 broken into 5a–5d on the plan. Erlang conformance 729/729.
 - **2026-05-28** — Step 4d: `bootstrap:build_genesis/1` + `verify_genesis/2` + `.cidhash` helpers in `next/kernel/bootstrap.erl`. Bundle CID delegated to host `cid:to_string` over `{genesis_bundle, Sections}` — deterministic, ~59 byte CIDv1 binary. `verify_genesis/2` returns `ok` on match, `{error, {cid_mismatch, Got, Expected}}` on drift. `write_cidhash`/`read_cidhash` persist the CID to a `.cidhash` sibling file (path hand-spelled `<<...,47,46,99,...>>` per the string-literal-in-binary substrate quirk). `next/tests/bootstrap_build.sh` 12/12. Erlang conformance 729/729.
 - **2026-05-27** — Step 4c: `next/kernel/bootstrap.erl` — Erlang module that enumerates the genesis bundle by walking seven hardcoded section subdirs via `file:list_dir/1`, filters `.sx` files via byte-pattern suffix match (`ends_with_sx/1`), reads each into a binary via `file:read_file/1`. Returns `{ok, [{Section, [{Name, Bytes}, ...]}]}`. Hits the same SX-parser substrate gap as Step 3b — kept the surface byte-only; parsing happens via SX-side helpers in later steps. Port gotchas: `fun name/arity` references unsupported (use anonymous fun wrappers); `<<"...">>` string-literal segments truncate to one byte (paths hand-spelled as integer-segment binaries). `next/tests/bootstrap_read.sh` 15/15. Erlang conformance 729/729.
 - **2026-05-27** — Step 4b-cod: bootstrap codecs + sig-suites + audience predicates complete. 3 `DefineCodec` files (dag-cbor + raw + dag-json, dag-cbor + dag-json deferring to host-codec primitive when wired), 2 `DefineSigSuite` files (rsa-sha256-2018 PEM-keyed, ed25519-2020 multibase-keyed, both :verify returning false as m2-deferred stand-in), 3 `DefineAudience` files (Public/Followers/Direct member-of predicates per design §16). Manifest now lists 26 bootstrap files across all eight sections; `next/tests/genesis_parse.sh` 50/50. Step 4b complete; remaining Step 4 is bundler code (4c–4e). Erlang conformance 729/729.