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

next/kernel/pipeline.erl

@@ -1,7 +1,8 @@
 -module(pipeline).
 -export([run_stages/2,
          validate_inbound/1, validate_outbound/1,
-         inbound_stages/0, outbound_stages/0]).
+         inbound_stages/0, outbound_stages/0,
+         stage_envelope/1]).
 
 %% Validation pipeline per design §14.
 %%
@@ -33,5 +34,16 @@ validate_inbound(Activity) ->
 validate_outbound(Activity) ->
     run_stages(Activity, outbound_stages()).
 
-inbound_stages()  -> [].
-outbound_stages() -> [].
+inbound_stages() ->
+    [fun (A) -> stage_envelope(A) end].
+
+outbound_stages() ->
+    [fun (A) -> stage_envelope(A) end].
+
+%% ── Concrete stages ─────────────────────────────────────────────
+
+%% stage_envelope/1 — wrap envelope:validate_shape/1. The pipeline
+%% driver expects ok | {error, R}; validate_shape returns exactly
+%% that, so delegation is direct.
+stage_envelope(Activity) ->
+    envelope:validate_shape(Activity).