## Why
Investment and retirement accounts show balance over time, but there's
no way to see how much money was actually put in versus how much is
current value. Users can't tell at a glance whether their investments
are up or down.
## What
Adds an "invested amount" tracking system across the full stack:
**Backend**
- New `invested_amount` column on `account_balances` (nullable
bigInteger, cents, per-date)
- Auto-sync from providers: Indexa Capital (instruments_cost +
cash_amount), Bitpanda (fiat deposit/withdrawal history), Binance
(90-day windowed deposit/withdrawal with crypto→fiat conversion)
- Manual input support via Update Balance dialog
- Historical invested amount data in all balance evolution APIs (net
worth, account detail)
**Frontend**
- Dashed line on sparkline charts (dashboard + accounts page) showing
per-point historical invested amount alongside balance
- Dashed line on account detail charts (daily AreaChart + monthly
ComposedChart)
- Tooltips with labeled rows: Balance, Invested, Gain/loss (color-coded)
- Invested amount column in balances history modal
- Invested amount field in balance import wizard (CSV mapping)
- Demo account seeder updated with invested amount data
## Screenshots
<img width="1301" height="750" alt="image"
src="https://github.com/user-attachments/assets/0f05ecd0-8b98-47b4-9fa4-027f0311e3bb"
/>
<img width="744" height="374" alt="image"
src="https://github.com/user-attachments/assets/c4daa816-dee0-4f94-957f-317a13bc80d5"
/>
<img width="1267" height="738" alt="image"
src="https://github.com/user-attachments/assets/21df350c-6954-4ff5-8b3c-b858df3a8b3a"
/>
<img width="1301" height="828" alt="image"
src="https://github.com/user-attachments/assets/16f5f021-a926-4e8e-a999-c4ca32d1ea3d"
/>
<img width="1274" height="845" alt="image"
src="https://github.com/user-attachments/assets/62f2dfc0-04f0-4bdb-b072-cf7cd1be77d3"
/>
## Summary
- Allow users to connect their Indexa Capital (Spanish robo-advisor)
account via API token
- Adds "Indexa Capital" option when selecting Spain in the bank
connection dialog
- Token-based auth flow: user enters API token (instead of OAuth
redirect), validated against Indexa API, stored encrypted
- Syncs portfolio balance only (no transactions) from the
`/accounts/{id}/performance` endpoint
- Accounts created as `Investment` type
- Reuses existing account mapping flow when the `account-mapping`
feature flag is active
- Disconnect flow skips session revocation for Indexa (no OAuth session
to revoke)
## New files
- `IndexaCapitalClient` — HTTP client for Indexa Capital API
(`X-AUTH-TOKEN`)
- `IndexaCapitalBalanceSyncService` — Syncs portfolio value into
`account_balances`
- `IndexaCapitalController` — Token validation + connection creation
- `ConnectIndexaCapitalRequest` — Form request validation
- Migration adding encrypted `api_token` column to `banking_connections`
## Test plan
- [x] 6 controller tests (connect, invalid token, mapping, feature flag,
validation, multi-account)
- [x] 4 balance sync tests (sync, update, skip, missing field)
- [x] 3 sync job tests (balance-only, no expire, no email for Indexa)
- [x] 1 disconnect test (no revokeSession for Indexa)
- [x] All 530 existing tests still pass
Víctor Falcón