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>
Pydantic v2's model_dump(mode="json") serializes Decimal as strings (e.g.,
"33.33" instead of 33.33), causing frontend crashes when calling .toFixed()
on string values. Introduced FloatDecimal type alias with PlainSerializer
to ensure Decimal fields are serialized as floats in JSON responses.
Also fixed frontend Transaction interface to match backend field names
(created_at → executed_at, transaction_type → tx_type).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
