Play the config watch in the package seats' whole test, so the held callers list is proven (issue 1966)

The holder holds its callers by a config watch since the callers were moved off per-call reads; the test's player answered only provision.get.

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

modules/gitea/cmd/package-registry/whole_integration_test.go

@@ -6,7 +6,7 @@ package main
 // the built package-registry bundle, played over its real stdin and stdout as the node's tool runtime plays it, its
 // `incoming` an object store and its `transfers` and `findings` key-value buckets of a nats-server of this test alone
 // (so the publish in parts runs through mesh-sdk's parts.BusObjects and BusTransfers, ruling 4 of the lead's 14:0x), the
-// builder's builder_versions answered on mesh/ask, the config value `callers` on mesh/provision.get, and the forge an
+// builder's builder_versions answered on mesh/ask, the config value `callers` watched on mesh/provision.watch, and the forge an
 // httptest server that takes reads only with the tools' token and writes only with the packages account's.
 //
 // A Go package the builder numbered goes up in two chunks, is uploaded whole as the packages account and says
@@ -123,8 +123,12 @@ func (p *player) handle(m wire) {
 		_ = json.Unmarshal(a.Body, &q)
 		d, ok := p.numbered[q.Name+"@"+q.Version]
 		p.answer(m.ID, map[string]any{"recorded": ok && d == q.Digest, "why": "not numbered with that digest"}, nil)
-	case m.Method == "mesh/provision.get" && a.Kind == "config":
-		p.answer(m.ID, nil, nil) // `callers` unset: design 51's list
+	case m.Method == "mesh/provision.watch" && a.Kind == "config":
+		// The watch of `callers`, as the runtime answers it: the value now as one change (mesh/provision,
+		// named by the watch's id) handed over before the watch is answered, here unset, so design 51's list holds.
+		p.send(map[string]any{"id": "change-" + watchID(m.ID), "method": "mesh/provision", "params": map[string]any{
+			"watch": watchID(m.ID), "change": map[string]any{"kind": "config", "key": a.Key}}})
+		p.answer(m.ID, map[string]any{}, nil)
 	case m.Method == "mesh/seat.publish":
 		p.answer(m.ID, map[string]any{}, p.nc.Publish(a.Subject, a.Body))
 	case m.Method == "mesh/publish":
@@ -138,6 +142,15 @@ func (p *player) handle(m wire) {
 	}
 }
 
+// watchID is the watch's id as a string, the form the change names it by.
+func watchID(raw json.RawMessage) string {
+	var id string
+	if json.Unmarshal(raw, &id) != nil {
+		return string(raw)
+	}
+	return id
+}
+
 func (p *player) objects(m wire, local, name string, data []byte) {
 	os, err := p.js.ObjectStore(p.ctx, "gitea_"+local)
 	if err != nil {