Merge branch 'main' into pr-747

nanobot/agent/context.py

@@ -225,14 +225,18 @@ To recall past events, grep {workspace_path}/memory/HISTORY.md"""
         Returns:
             Updated message list.
         """
-        msg: dict[str, Any] = {"role": "assistant", "content": content or ""}
-        
+        msg: dict[str, Any] = {"role": "assistant"}
+
+        # Omit empty content — some backends reject empty text blocks
+        if content:
+            msg["content"] = content
+
         if tool_calls:
             msg["tool_calls"] = tool_calls
-        
-        # Thinking models reject history without this
+
+        # Include reasoning content when provided (required by some thinking models)
         if reasoning_content:
             msg["reasoning_content"] = reasoning_content
-        
+
         messages.append(msg)
         return messages

nanobot/agent/tools/cron.py

@@ -50,6 +50,10 @@ class CronTool(Tool):
                     "type": "string",
                     "description": "Cron expression like '0 9 * * *' (for scheduled tasks)"
                 },
+                "tz": {
+                    "type": "string",
+                    "description": "IANA timezone for cron expressions (e.g. 'America/Vancouver')"
+                },
                 "at": {
                     "type": "string",
                     "description": "ISO datetime for one-time execution (e.g. '2026-02-12T10:30:00')"
@@ -68,30 +72,46 @@ class CronTool(Tool):
         message: str = "",
         every_seconds: int | None = None,
         cron_expr: str | None = None,
+        tz: str | None = None,
         at: str | None = None,
         job_id: str | None = None,
         **kwargs: Any
     ) -> str:
         if action == "add":
-            return self._add_job(message, every_seconds, cron_expr, at)
+            return self._add_job(message, every_seconds, cron_expr, tz, at)
         elif action == "list":
             return self._list_jobs()
         elif action == "remove":
             return self._remove_job(job_id)
         return f"Unknown action: {action}"
     
-    def _add_job(self, message: str, every_seconds: int | None, cron_expr: str | None, at: str | None) -> str:
+    def _add_job(
+        self,
+        message: str,
+        every_seconds: int | None,
+        cron_expr: str | None,
+        tz: str | None,
+        at: str | None,
+    ) -> str:
         if not message:
             return "Error: message is required for add"
         if not self._channel or not self._chat_id:
             return "Error: no session context (channel/chat_id)"
+        if tz and not cron_expr:
+            return "Error: tz can only be used with cron_expr"
+        if tz:
+            from zoneinfo import ZoneInfo
+            try:
+                ZoneInfo(tz)
+            except (KeyError, Exception):
+                return f"Error: unknown timezone '{tz}'"
         
         # Build schedule
         delete_after = False
         if every_seconds:
             schedule = CronSchedule(kind="every", every_ms=every_seconds * 1000)
         elif cron_expr:
-            schedule = CronSchedule(kind="cron", expr=cron_expr)
+            schedule = CronSchedule(kind="cron", expr=cron_expr, tz=tz)
         elif at:
             from datetime import datetime
             dt = datetime.fromisoformat(at)