feat(api): content.load_npc + content-root resolver

api/app/content.py

@@ -8,6 +8,7 @@ scenes into play.
 """
 
 import json
+import os
 from pathlib import Path
 
 
@@ -48,3 +49,30 @@ def unresolved_refs(origin: dict, world: dict[str, set[str]]) -> list[str]:
         if npc_id not in world["npcs"]:
             missing.append(f"npc:{npc_id}")
     return missing
+
+
+def _content_root() -> Path:
+    """Locate the authored content root. Honours CONTENT_ROOT, else walks up
+    from this file for a dir containing world/ — repo-root/content in a local
+    checkout, /app/content when bundled into the Docker image. Mirrors
+    canon_log._schema_dir().
+    """
+    env = os.environ.get("CONTENT_ROOT")
+    if env:
+        return Path(env)
+    here = Path(__file__).resolve()
+    for parent in here.parents:
+        candidate = parent / "content"
+        if (candidate / "world").is_dir():
+            return candidate
+    raise RuntimeError("content root not found")
+
+
+def load_npc(npc_id: str) -> dict | None:
+    """Load one NPC's authored file (persona + knowledge + capabilities), or
+    None if no file resolves. Server-only fields never travel to the client."""
+    path = _content_root() / "world" / "npcs" / f"{npc_id}.json"
+    if not path.is_file():
+        return None
+    with open(path) as f:
+        return json.load(f)