feat(nest): POST/GET nest messages, Jev-first tagging, event-driven crow response (#10)

hub.go

@@ -116,6 +116,22 @@ func (h *Hub) Publish(listID, name string, fields map[string]any) {
 	}
 }
 
+// OpenNest lazily opens a stream for a nest's conversation. Nest ids are
+// slugs and list ids are hex, so the same map serves both without collision.
+func (h *Hub) OpenNest(nestID string) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	if h.lists[nestID] == nil {
+		h.lists[nestID] = &listStream{created: time.Now(), subs: map[chan sseMsg]struct{}{}}
+	}
+}
+
+// PublishNest records one nest event and sends it to subscribers.
+func (h *Hub) PublishNest(nestID, name string, fields map[string]any) {
+	h.OpenNest(nestID)
+	h.Publish(nestID, name, fields)
+}
+
 // Subscribe returns the history after lastID and a channel for what comes next.
 // The channel closes if the subscriber falls too far behind.
 func (h *Hub) Subscribe(listID string, lastID int) ([]sseMsg, chan sseMsg, bool) {