Projects live at URLs, have owners, and are edited together live

A project is only ever at /p/<id>/<slug>; / is the index of the projects
you own or edit. Every project has an owner, who can name editors;
anyone with the link can view. Every edit saves itself, one request in
flight at a time, as a patch of the leaves that changed, and a websocket
(channels + daphne) carries presence and each committed write to
everyone else in the project. The first write to a leaf wins, and the
loser is told.

Undo is per person: a step undoes only if the leaves it touched still
hold what it left, so it never takes a collaborator's work with it.
Named snapshots replace saving, and restore as an ordinary write.

An empty symbol now survives the leaf round trip with `:nodes {}`.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/asgi.py

@@ -1,12 +1,25 @@
 """ASGI entry point.
 
-ASGI and not only WSGI because the collaboration design in docs/architecture.md
-puts presence and document deltas on a websocket. Those consumers are out of step
-9's scope; this is the half of their setup that costs nothing now.
+HTTP is Django as usual. The websocket carries presence and the document deltas
+the server broadcasts after a write — never writes, which stay on HTTP. See
+docs/architecture.md, Collaboration.
 """
 import os
 
 from django.core.asgi import get_asgi_application
 
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "server.settings")
-application = get_asgi_application()
+django_asgi_app = get_asgi_application()
+
+from channels.auth import AuthMiddlewareStack  # noqa: E402
+from channels.routing import ProtocolTypeRouter, URLRouter  # noqa: E402
+from channels.security.websocket import AllowedHostsOriginValidator  # noqa: E402
+
+from clips.routing import websocket_urlpatterns  # noqa: E402
+
+application = ProtocolTypeRouter({
+    "http": django_asgi_app,
+    "websocket": AllowedHostsOriginValidator(
+        AuthMiddlewareStack(URLRouter(websocket_urlpatterns))
+    ),
+})