fix: wire TraceStore to event bus and pass to AgentExecutor (#187)

Closes #179 — traces were never persisted in the serve path because:
1. TraceStore.subscribe_to_bus() was never called in app.py
2. AgentExecutor was constructed without trace_store in serve.py and
   agent_manager_routes.py
3. The /v1/traces API returned raw dataclass fields instead of the
   frontend-expected format

Fixes all three: wires bus subscription, passes trace_store to all
executor instantiation sites, and adds _serialise_trace() for proper
API response formatting.

src/openjarvis/cli/serve.py

@@ -344,7 +344,20 @@ def serve(
             from openjarvis.agents.executor import AgentExecutor
             from openjarvis.agents.scheduler import AgentScheduler
 
-            executor = AgentExecutor(manager=agent_manager, event_bus=bus)
+            _trace_store = None
+            try:
+                if config.traces.enabled:
+                    from openjarvis.traces.store import TraceStore
+
+                    _trace_store = TraceStore(db_path=config.traces.db_path)
+            except Exception:
+                pass
+
+            executor = AgentExecutor(
+                manager=agent_manager,
+                event_bus=bus,
+                trace_store=_trace_store,
+            )
             from openjarvis.system import SystemBuilder
 
             system = SystemBuilder(config).build()

src/openjarvis/server/agent_manager_routes.py

@@ -1156,9 +1156,11 @@ def create_agent_manager_router(
                 from openjarvis.agents.executor import AgentExecutor
                 from openjarvis.core.events import get_event_bus
 
+                _ts = getattr(request.app.state, "trace_store", None)
                 executor = AgentExecutor(
                     manager=manager,
                     event_bus=get_event_bus(),
+                    trace_store=_ts,
                 )
                 system = _make_lightweight_system(
                     server_engine,
@@ -1501,9 +1503,11 @@ def create_agent_manager_router(
                     _srv_model,
                 )
                 try:
+                    _ts2 = getattr(request.app.state, "trace_store", None)
                     executor = AgentExecutor(
                         manager=manager,
                         event_bus=get_event_bus(),
+                        trace_store=_ts2,
                     )
                     system = _make_lightweight_system(
                         _srv_engine,

src/openjarvis/server/api_routes.py

@@ -196,17 +196,37 @@ async def memory_stats(request: Request):
 traces_router = APIRouter(prefix="/v1/traces", tags=["traces"])
 
 
+def _serialise_trace(trace) -> dict:
+    """Convert a Trace dataclass to a frontend-friendly dict."""
+    import datetime
+    from dataclasses import asdict
+
+    d = asdict(trace)
+    d["id"] = d.pop("trace_id", "")
+    started = d.pop("started_at", 0.0)
+    d["created_at"] = (
+        datetime.datetime.fromtimestamp(started, tz=datetime.timezone.utc).isoformat()
+        if started
+        else None
+    )
+    dur = d.pop("total_latency_seconds", 0.0)
+    d["duration_ms"] = round(dur * 1000)
+    for step in d.get("steps", []):
+        st = step.get("step_type")
+        if hasattr(st, "value"):
+            step["step_type"] = st.value
+    return d
+
+
 @traces_router.get("")
 async def list_traces(request: Request, limit: int = 20):
     """List recent traces."""
     try:
-        from dataclasses import asdict
-
         store = getattr(request.app.state, "trace_store", None)
         if store is None:
             return {"traces": []}
         traces = store.list_traces(limit=limit)
-        items = [asdict(t) for t in traces]
+        items = [_serialise_trace(t) for t in traces]
         return {"traces": items}
     except Exception as exc:
         return {"traces": [], "error": str(exc)}
@@ -216,15 +236,13 @@ async def list_traces(request: Request, limit: int = 20):
 async def get_trace(trace_id: str, request: Request):
     """Get a specific trace by ID."""
     try:
-        from dataclasses import asdict
-
         store = getattr(request.app.state, "trace_store", None)
         if store is None:
             raise HTTPException(status_code=404, detail="Trace not found")
         trace = store.get(trace_id)
         if trace is None:
             raise HTTPException(status_code=404, detail="Trace not found")
-        return asdict(trace)
+        return _serialise_trace(trace)
     except HTTPException:
         raise
     except Exception as exc:

src/openjarvis/server/app.py

@@ -215,7 +215,11 @@ def create_app(
 
         cfg = config if config is not None else load_config()
         if cfg.traces.enabled:
-            app.state.trace_store = TraceStore(db_path=cfg.traces.db_path)
+            _trace_store = TraceStore(db_path=cfg.traces.db_path)
+            app.state.trace_store = _trace_store
+            _bus = getattr(app.state, "bus", None)
+            if _bus is not None:
+                _trace_store.subscribe_to_bus(_bus)
     except Exception:
         pass  # traces are optional; don't block server startup