Dashboard: surface the real compute_fleet error in the response (0.38.2)

The fleet endpoint returned a bare 500, so the error banner only showed
"status code 500" with no cause. Wrap the call to log the full traceback
server-side and return the exception type, message and originating
file:line in the HTTP detail, so the dashboard banner pinpoints the
failure for an authenticated user.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/routers/dashboard.py

@@ -1,7 +1,10 @@
 """Dashboard aggregation endpoint (fleet-wide cockpit data)."""
 from __future__ import annotations
 
-from fastapi import APIRouter, Depends
+import logging
+import traceback
+
+from fastapi import APIRouter, Depends, HTTPException
 from sqlmodel import Session
 
 from auth import get_current_user
@@ -9,6 +12,8 @@ from database import get_session
 from models.user import User
 from services import dashboard_service
 
+logger = logging.getLogger("stackpilot.dashboard")
+
 router = APIRouter(prefix="/api/dashboard", tags=["dashboard"])
 
 
@@ -20,4 +25,15 @@ async def fleet(
 ) -> dict:
     """Fleet-wide 'needs attention' list, KPIs and per-host rollup across the
     local host and every agent — the data behind the operator cockpit."""
-    return await dashboard_service.compute_fleet(session, refresh=refresh)
+    try:
+        return await dashboard_service.compute_fleet(session, refresh=refresh)
+    except Exception as exc:  # noqa: BLE001 — surface the real cause for diagnosis
+        logger.exception("compute_fleet failed")
+        # Deepest frame pinpoints where it broke; safe to expose to the
+        # authenticated user and it makes the dashboard error banner actionable.
+        tb = traceback.extract_tb(exc.__traceback__)
+        where = f" at {tb[-1].filename.split('/')[-1]}:{tb[-1].lineno}" if tb else ""
+        raise HTTPException(
+            status_code=500,
+            detail=f"{type(exc).__name__}: {exc}{where}",
+        ) from exc

backend/version.py

@@ -1,3 +1,3 @@
 """Single source of truth for the StackPilot release version."""
 
-APP_VERSION = "0.38.1"
+APP_VERSION = "0.38.2"

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "stackpilot-frontend",
   "private": true,
-  "version": "0.38.1",
+  "version": "0.38.2",
   "type": "module",
   "scripts": {
     "dev": "vite",