Fix WebSocket disconnect crash and missing 'personality' field

Two bugs that crashed the engine in production:

1. world.nearby_agents() did not SELECT the 'personality' column, so
   _reaction_turn raised KeyError on every reactive trigger, killing the
   engine thread silently. Engine-Thread stieg aus ohne Log.

   Fix: select personality and json-parse it so callers get a real list,
   matching agents_mod.get().

2. server.py ws() handler caught the generic 'Exception' from
   asyncio.to_thread(queue.get) and tried to send a ping back, but the
   WebSocket was already closed by the client. Starlette raised
   RuntimeError: Cannot call 'send' once a close message has been sent.

   Fix: drop the ping, just break the loop on any exception. Client
   disconnect now handled cleanly.

Live-verified: 0 errors in log after 3 abrupt disconnects, engine
continues producing ticks.

engine/world.py

@@ -95,7 +95,8 @@ def nearby_agents(agent_id: str, x: int, y: int, radius: float = HEARING_DISTANC
     c.row_factory = sqlite3.Row
     try:
         rows = c.execute(
-            "SELECT id,name,x,y,energy FROM agents WHERE id!=? AND alive=1", (agent_id,)
+            "SELECT id,name,personality,x,y,energy FROM agents "
+            "WHERE id!=? AND alive=1", (agent_id,)
         ).fetchall()
         out = []
         for r in rows:
@@ -103,6 +104,12 @@ def nearby_agents(agent_id: str, x: int, y: int, radius: float = HEARING_DISTANC
             if d <= radius:
                 d2 = dict(r)
                 d2["distance"] = d
+                # personality is stored as a JSON string; parse so callers
+                # get a real list (matches agents_mod.get).
+                try:
+                    d2["personality"] = json.loads(d2.get("personality") or "[]")
+                except Exception:
+                    d2["personality"] = []
                 out.append(d2)
         return out
     finally:

server.py

@@ -164,8 +164,10 @@ async def ws(ws: WebSocket):
             try:
                 msg = await asyncio.to_thread(queue.get, timeout=30.0)
                 await ws.send_json(msg)
+            except WebSocketDisconnect:
+                break
             except Exception:
-                # heartbeat
-                await ws.send_json({"type": "ping", "ts": time.time()})
+                # client went away — stop sending
+                break
     except WebSocketDisconnect:
         pass