rename from checkpoint to timeline agent

app/core/output_formatter.py

@@ -27,7 +27,7 @@ _VALID_CHART_TYPES = {"area", "bar", "line", "pie", "radar", "radial"}
 # Map agent name → floating domain
 _AGENT_DOMAIN: dict[str, str] = {
     "task_agent": "tasks",
-    "checkpoint_agent": "checkpoints",
+    "timeline_agent": "timelines",
     "note_agent": "notes",
     "project_agent": "projects",
 }
@@ -171,8 +171,8 @@ class HomeFormatter:
             )
 
         if block_type == "timeline":
-            if not isinstance(obj.get("checkpoints"), list):
-                logger.warning("HomeFormatter: timeline missing checkpoints — skipping")
+            if not isinstance(obj.get("timelines"), list):
+                logger.warning("HomeFormatter: timeline missing timelines — skipping")
                 return None
             return WsStreamBlock(
                 request_id=self.request_id,