fed-sx-m1: Step 7c — outbox:publish broadcasts to projection processes + 14 tests

next/kernel/outbox.erl

@@ -91,12 +91,23 @@ publish(Request, Context) ->
     case pipeline:run_stages(Signed, Stages) of
         ok ->
             {ok, NewLog, _Seq} = log:append(LogState, Signed),
+            broadcast(Signed, envelope_field(projections, Context)),
             Result = [{cid, cid_of(Signed)}, {activity, Signed}],
             {ok, Result, NewLog};
         {error, Reason} ->
             {error, Reason, LogState}
     end.
 
+%% broadcast/2 — fire-and-forget cast to each named projection.
+%% Missing/nil/empty list is a no-op; the publish API does not
+%% require projections to exist. Activity is the post-sign Signed
+%% envelope (same value that landed in the log).
+broadcast(_Activity, nil) -> ok;
+broadcast(_Activity, []) -> ok;
+broadcast(Activity, [Name | Rest]) ->
+    projection:async_fold(Name, Activity),
+    broadcast(Activity, Rest).
+
 envelope_field(K, PL) ->
     case envelope:get_field(K, PL) of
         {ok, V}   -> V;