feat(content): promote Duncarrow; build client/server artifacts

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HuHRPE7VfppUJEaoGBEUqZ

content/server/topics/travelers-go-missing.json

@@ -0,0 +1,5 @@
+{
+  "body": "Small parties on the north road \u2014 always small, always few enough not to be missed \u2014 sometimes don't arrive where they were going. Locals know it as bad luck on a bad stretch of road. They do not like discussing it.",
+  "id": "rumor.travelers-go-missing",
+  "secrecy": 2
+}