Serve a module's log verbs so its record outlives a bucket's cap and the events' week (ADR 0297, issues 501, 502)

The runtime answers mesh/log.append, read, last and info for a log issued
in the module's membership, by publish, batch direct get and stream info
alone. A stale expect is refused as a lost state update, so a module tells
it by the same code.

node-tools/internal/launch/event_answer_test.go

@@ -37,6 +37,7 @@ type subscribing struct {
 func (b *subscribing) Publish(json.RawMessage) error                          { return nil }
 func (b *subscribing) Ask(json.RawMessage) (json.RawMessage, error)           { return nil, nil }
 func (b *subscribing) State(string, json.RawMessage) (json.RawMessage, error) { return nil, nil }
+func (b *subscribing) Log(string, json.RawMessage) (json.RawMessage, error)   { return nil, nil }
 func (b *subscribing) Watch(json.RawMessage, func(json.RawMessage) error) (func(), error) {
 	return func() {}, nil
 }

node-tools/internal/launch/launch.go

@@ -77,6 +77,8 @@ type Bus interface {
 	Subscribe(deliver func(envelope json.RawMessage) error) error
 	State(verb string, params json.RawMessage) (json.RawMessage, error)
 	Watch(params json.RawMessage, deliver func(change json.RawMessage) error) (stop func(), err error)
+	// Log answers a bundle's `append`, `read`, `last` and `info` on its module's log (novox/hq ADR 0297).
+	Log(verb string, params json.RawMessage) (json.RawMessage, error)
 	// Seat answers a bundle's seat traffic (novox/hq ADR 0259 §3): `publish`, `prove` and `record` at once;
 	// `take` and `answer` bind once and hand each message or proof on through handOn, to whichever child
 	// of the module asked last — a restarted child asks again as its code runs again.
@@ -288,6 +290,11 @@ func Start(module, entry string, env []string, mesh Bus, logf func(string, ...an
 							if answered, err = mesh.State(strings.TrimPrefix(m.Method, "mesh/state."), m.Params); err == nil {
 								result = answered
 							}
+						case "mesh/log.append", "mesh/log.read", "mesh/log.last", "mesh/log.info":
+							var answered json.RawMessage
+							if answered, err = mesh.Log(strings.TrimPrefix(m.Method, "mesh/log."), m.Params); err == nil {
+								result = answered
+							}
 						case "mesh/state.watch":
 							// Each change is asked of this child, in order, naming the watch it is for by
 							// the id the child asked it with — two watches of one state are two handlers;