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/npcs/harn-blackwood.json

@@ -0,0 +1,18 @@
+{
+  "id": "npc.harn-blackwood",
+  "knows": [
+    {
+      "fact_id": "rumor.travelers-go-missing",
+      "gate": "warm"
+    },
+    {
+      "fact_id": "fact.harn-daughter-left",
+      "gate": "warm"
+    }
+  ],
+  "related": [
+    "town.duncarrow"
+  ],
+  "start_disposition": "neutral",
+  "type": "person"
+}