[verified] fix: preserve timestamps in chat history

plugin/pheby/hermes_bridge.py

@@ -9,6 +9,7 @@ so the module can be imported by unit tests without a Hermes install.
 from __future__ import annotations
 
 import asyncio
+import datetime as dt
 import logging
 import threading
 import time
@@ -206,8 +207,10 @@ async def list_conversations(server: Any = None) -> List[Dict[str, Any]]:
 
 def _iso(value: Any) -> Optional[str]:
     try:
+        if isinstance(value, (int, float)):
+            return dt.datetime.fromtimestamp(value, tz=dt.timezone.utc).isoformat()
         return value.isoformat() if value else None
-    except AttributeError:
+    except (AttributeError, OSError, OverflowError, TypeError, ValueError):
         return None
 
 
@@ -254,8 +257,7 @@ async def conversation_history(conversation_id: str, limit: int
                     if isinstance(row.get("_row_id"), (int, str)) else None,
                     "role": role,
                     "text": text,
-                    "ts": row.get("timestamp") if isinstance(
-                        row.get("timestamp"), str) else None,
+                    "ts": _iso(row.get("timestamp")),
                 })
             found = True
         except Exception: