The portfolio API was returning only ticker symbols (e.g., "095570")
without stock names. The Stock table already has Korean names
(e.g., "AJ네트웍스") from data collection.
Backend: Add name field to HoldingWithValue schema, fetch stock names
via RebalanceService.get_stock_names() in the portfolio detail endpoint.
Frontend: Show Korean stock name as primary label with ticker as
subtitle in portfolio detail, donut charts, and target vs actual
comparison. Dashboard donut chart also shows names.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
