feat: migrate chat orchestration to deep langgraph workers

app/agents/timeline_agent.py

@@ -2,17 +2,13 @@
 
 from __future__ import annotations
 
-import json
 from typing import Any
 
-from langchain_core.messages import HumanMessage, SystemMessage
 from langchain_core.tools import tool
 
-from app.core.agent_registry import ChatAgent, registry
-from app.core.llm import get_llm
 from app.core.ws_context import execute_on_client
 
-_SYSTEM_PROMPT = (
+TIMELINE_SYSTEM_PROMPT = (
     "You are a project timeline assistant. Timelines are milestone dates that\n"
     "track progress on a project — they are not calendar events.\n\n"
     "Rules:\n"
@@ -106,23 +102,9 @@ async def delete_timeline(timeline_id: str) -> str:
     return f"Timeline {timeline_id} deleted."
 
 
-@registry.register
-class TimelineAgent(ChatAgent):
-    def get_name(self) -> str:
-        return "timeline_agent"
-
-    def get_description(self) -> str:
-        return "Manages project timelines (milestones): list, create, update, delete"
-
-    def get_tools(self) -> list[Any]:
-        return [list_timelines, create_timeline, update_timeline, delete_timeline]
-
-    async def handle(self, query: str, context: dict[str, Any]) -> str:
-        llm = get_llm()
-        messages = [
-            SystemMessage(content=_SYSTEM_PROMPT),
-            HumanMessage(
-                content=f"User query: {query}\nContext: {json.dumps(context)[:1000]}"
-            ),
-        ]
-        return await self._tool_loop(llm, messages, self.get_tools())
+TIMELINE_TOOLS: list[Any] = [
+    list_timelines,
+    create_timeline,
+    update_timeline,
+    delete_timeline,
+]