Fix Inertia form save: return 303 redirect after POST

Inertia.js expects a 303 status code redirect after successful form
submissions. Also handle both JSON and form-encoded POST bodies.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: mattstratton

apps/events/manage_views.py

@@ -67,7 +67,12 @@ def event_edit(request, event_slug):
         return HttpResponseForbidden("You don't have permission to manage this event.")
 
     if request.method == "POST":
-        data = json.loads(request.body)
+        content_type = request.content_type or ""
+        if "application/json" in content_type:
+            data = json.loads(request.body)
+        else:
+            data = request.POST.dict()
+
         for field in ["description", "location_name", "location_address", "organizer_email",
                        "cfp_link", "registration_link", "social_twitter", "social_linkedin",
                        "social_mastodon", "social_bluesky"]:
@@ -77,7 +82,12 @@ def event_edit(request, event_slug):
             if field in data:
                 setattr(event, field, bool(data[field]))
         event.save()
-        return redirect(f"/manage/events/{event.slug}/")
+
+        # Inertia expects a 303 redirect after a successful POST
+        from django.http import HttpResponseRedirect
+        response = HttpResponseRedirect(f"/manage/events/{event.slug}/")
+        response.status_code = 303
+        return response
 
     # GET — render the edit page
     team_members = list(event.team_members.values(