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/world/canon/mayor-oswin-crell.json

@@ -0,0 +1,8 @@
+{
+  "body": "Mayor of Duncarrow for fifteen years. Warm, unhurried, remembers names and the names of your dead. Runs a clean council and a clean set of books. Widely liked. The visible locked door of this town: pleasant to every player at every disposition, and revealing of nothing.",
+  "id": "person.mayor-oswin-crell",
+  "related": [
+    "town.duncarrow"
+  ],
+  "type": "person"
+}