fed-sx-m1: Step 6b-env — pipeline:stage_envelope wired against envelope:validate_shape + 12 tests

plans/fed-sx-milestone-1.md

@@ -387,7 +387,8 @@ projection fold maintains it.)
 
 **Sub-deliverables:**
 - [x] **6a** — `pipeline:run_stages/2` driver — pure fold over a stage list of `(Activity) -> ok | {error, R}` funs, halts on first failure. `validate_inbound/1` + `validate_outbound/1` + `inbound_stages/0` + `outbound_stages/0` (empty lists for now). `next/tests/pipeline_driver.sh` (10 cases).
-- [ ] **6b** — Stage modules calling existing envelope module: `stage_envelope/1` (validate_shape), `stage_signature/1` (needs actor-state lookup — accept any signed proxy for v1)
+- [x] **6b-env** — `pipeline:stage_envelope/1` delegating to `envelope:validate_shape/1`; wired into both `inbound_stages` and `outbound_stages`. `next/tests/pipeline_envelope.sh` (12 cases); pipeline_driver.sh updated to test the driver in isolation.
+- [ ] **6b-sig** — `pipeline:stage_signature/2` taking actor-state context, delegating to `envelope:verify_signature/2`. Needs a runtime-context shape since the driver only passes the activity.
 - [ ] **6c** — `stage_replay/1` (checks the log for existing activity id), `stage_activity_schema/1` (registry lookup + schema body eval is deferred — placeholder)
 - [ ] **6d** — `outbox:publish/2`: envelope construction, sign, validate_outbound, log:append, returns `{ok, #{cid, ap_id}}`
 - [ ] **6e** — HTTP handler for POST /activity glue (depends on Step 8 http server)
@@ -968,6 +969,7 @@ 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 6b-env: `pipeline:stage_envelope/1` wraps `envelope:validate_shape/1`; wired into both `inbound_stages` and `outbound_stages` lists. `validate_inbound`/`validate_outbound` now exercises the full envelope shape contract end-to-end (missing fields, signature sub-shape, non-list input). `next/tests/pipeline_envelope.sh` 12/12; `pipeline_driver.sh` refactored to test the driver against explicit stage lists rather than depending on the now-non-empty defaults. Split 6b in the plan into 6b-env (done) + 6b-sig (needs runtime context for actor-state). Erlang conformance 729/729.
 - **2026-05-28** — Step 6a: `next/kernel/pipeline.erl` — validation pipeline driver per design §14. `run_stages/2` is a pure fold over `(Activity) -> ok | {error, R}` funs, halting on first failure. Halt verified by inserting a post-error stage that would set a contradictory tag if it ran. `validate_inbound/1` + `validate_outbound/1` wrappers; concrete stage lists are empty (6b wires `stage_envelope`/`stage_signature`). Port quirk: `Pattern = Var` match-alias syntax unsupported — split into separate `Result = X, case Result of ...`. `next/tests/pipeline_driver.sh` 10/10. Step 6 broken into 6a–6e on the plan. Erlang conformance 729/729.
 - **2026-05-28** — Step 5b: `registry.erl` extended with gen_server callbacks + named-process API. `start_link/0` spawns the worker, registers it under the literal `registry` atom, returns the Pid (port returns raw Pid not `{ok, Pid}` — diverges from OTP). 3-arity `register`, 2-arity `lookup`, 1-arity `list` delegate to the pure /4 and /3 functions inside handle_call. Port note documented: `?MODULE` macro unsupported; tests must inline start_link with operations since spawned processes don't persist across separate `erlang-eval-ast` calls. `next/tests/registry_server.sh` 12/12. Erlang conformance 729/729.
 - **2026-05-28** — Step 4e: `bootstrap:load_genesis/1` + `strip_sx_suffix/1` in `next/kernel/bootstrap.erl`. Walks `read_genesis` output and threads each entry through `registry:register/4`, using the section atom as the kind and the filename-minus-`.sx` as the entry name. Per-kind counts match the seven bootstrap sections exactly (3/10/7/3/3/2/3 = 31 entries total). `next/tests/bootstrap_load.sh` 15/15. Determinism verified by comparing `cid:to_string` of the loaded state across calls (faster than deep-equality on the nested-binary state). Step 4 is now complete end-to-end except for SX-source parsing of the loaded entries. Erlang conformance 729/729.