Add lightweight analytics dashboard

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

README.md

@@ -156,8 +156,14 @@ Each job payload includes:
 - Read-only dashboard (no run controls)
 - Requires token input
 - Live updates via `/ws`
+- Analytics dashboards for success rate by objective category and daily averages
 - Set `DISABLE_UI=true` to disable UI
 
+### Analytics API
+
+- `GET /api/analytics`
+- Returns objective-category success rates plus average steps/cost over time
+
 ## Agent Instructions (Practical)
 
 - Prefer `execute_command` for deterministic actions (opening URLs, filesystem checks).