feat(langfuse): propagate user_id and session_id to all traces

- Add hash_user_id() to SHA-256 hash user IDs before sending to Langfuse
- Add langfuse_context() helper wrapping propagate_attributes()
- deep_agent: extract session_id from _debug context, wrap all agent
  runs and classifier with langfuse_context(user_id, session_id)
- agent_runner: add session_id param, pass run_id as session for batch
- agent_setup: wrap journey LLM calls with langfuse_context
- Remove redundant metadata dicts (now handled by propagate_attributes)

app/api/routes/agent_setup.py

@@ -32,7 +32,7 @@ from typing import Any
 from langchain_core.messages import AIMessage, HumanMessage, SystemMessage, ToolMessage
 
 from app.agents.filesystem_agent import make_directory_tools
-from app.core.langfuse_client import compile_prompt, extract_usage, get_langfuse, get_prompt_or_fallback
+from app.core.langfuse_client import compile_prompt, extract_usage, get_langfuse, get_prompt_or_fallback, langfuse_context
 from app.core.llm import get_agent_llm, model_for_agent
 from app.schemas import AgentConfig
 
@@ -260,11 +260,13 @@ async def _call_llm_with_tools(
     llm_with_tools = llm.bind_tools(tools)
     tool_map = {tool_def.name: tool_def for tool_def in tools}
 
+    _lf_ctx = langfuse_context(user_id=user_id or None, session_id=session_id or None)
+    _lf_ctx.__enter__()
+
     _span_ctx = (
         lf.start_as_current_observation(
             as_type="span",
             name="journey-setup",
-            metadata={"user_id": user_id or None, "session_id": session_id or None},
             input=history[-1]["content"] if history else "",
         )
         if lf else None
@@ -286,7 +288,7 @@ async def _call_llm_with_tools(
             _gen = _gen_ctx.__enter__() if _gen_ctx else None
             response: AIMessage = await llm_with_tools.ainvoke(messages)
             if _gen_ctx:
-                _gen.update(output=_as_text(response.content), usage=extract_usage(response))
+                _gen.update(output=_as_text(response.content), usage_details=extract_usage(response))
                 _gen_ctx.__exit__(None, None, None)
 
             resp_text = _as_text(response.content)
@@ -342,6 +344,7 @@ async def _call_llm_with_tools(
     finally:
         if _span_ctx:
             _span_ctx.__exit__(None, None, None)
+        _lf_ctx.__exit__(None, None, None)
         if lf:
             lf.flush()
 

app/api/routes/agents.py

@@ -12,9 +12,12 @@ in backend agent-config tables.
 from __future__ import annotations
 
 import asyncio
+import logging
 import uuid
 from datetime import datetime, timedelta, timezone
 
+logger = logging.getLogger(__name__)
+
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -182,7 +185,6 @@ async def trigger_agent_run(
         if body.last_run_at
         else None
     )
-
     config = LocalAgentConfig(
         id=str(uuid.uuid4()),
         user_id=current_user.id,