id: PORT-003
title: Historical LTV Chart
status: done
priority: P2
effort: M
depends_on:
  - PORT-001
tags:
  - portfolio
  - history
  - charts
summary: Workspace-scoped LTV snapshots are now recorded over time and rendered on the overview page with CSV export.
completed_notes:
  - Added structured workspace-scoped LTV snapshot persistence in `app/models/ltv_history.py`.
  - Added chart-range and CSV export support in `app/services/ltv_history.py`.
  - Updated `app/pages/overview.py` to record snapshots, display 7/30/90 day LTV charts with the margin threshold line, and expose `Export CSV`.
  - Added focused regression coverage in `tests/test_ltv_history.py` for persistence, same-day replacement, range filtering, and CSV export.
  - Added a Playwright regression test in `tests/test_overview_ltv_history_playwright.py` covering the exact changed route, live rendered chart series on the overview page, and CSV download path on `/{workspace_id}`.
  - Manual local Docker validation confirmed the stack starts cleanly, `/health` returns OK, and the Docker-served overview route renders the LTV history UI without visible runtime errors.