## 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
3f541ca4d6