fix(i18n): translate Unknown Income/Expense and other missing ES strings (#331)
## Summary
Fixes untranslated strings surfaced in the Spanish UI (e.g. `Unknown
Income`, `Unknown Expense` on the cashflow breakdown).
## Root cause
`CashflowAnalyticsController` pushed literal English names into the API
response for uncategorized totals, bypassing `__()`. Additional `__()`
calls across the sync flow and validation had no matching keys in
`lang/es.json`. Several frontend toasts/errors were also hardcoded.
## Changes
**Controller (P0)**
- `app/Http/Controllers/Api/CashflowAnalyticsController.php` — wrap
`Unknown Income`/`Unknown Expense` with `__()` (lines 250, 323).
**Translations (P0 + P1 + P2)**
- `lang/es.json` — added 23 keys (1730 → 1753):
- `Unknown Income`, `Unknown Expense`, `Unknown Bank`, `Unknown error`
- Sync/banking messages: `Invalid credentials…`, `Rate limit exceeded…`,
`Failed to sync with the provider…`, `The provider is experiencing
issues…`, `An unexpected error occurred during sync…`, `Credentials
updated. Sync started.`, `Action required: :provider connection needs
attention`, `:count new transactions synced on Whisper Money`
- Validation: `The selected property cannot be linked.`, `The selected
property is already linked to a loan.`, `The verification link is
invalid.`, `This field is required.`
- Misc: `Confirm your waitlist spot - Whisper Money`, `Log in to your
bank`
- Frontend toasts: `Failed to re-evaluate rules. Please try again.`,
`Failed to load import data`, `All transactions failed to import`,
`Failed to update transactions`, `Failed to update transactions with
labels`
**Frontend hardcoded strings wrapped in `__()` (P2)**
- `resources/js/components/transactions/import-transactions-drawer.tsx`
- `resources/js/components/accounts/import-balances-drawer.tsx`
- `resources/js/lib/sync-manager.ts` (added `@/utils/i18n` import)
- `resources/js/components/transactions/transaction-list.tsx`
- `resources/js/components/transactions/import-transactions-button.tsx`
- `resources/js/pages/transactions/index.tsx`
## Verification
- `vendor/bin/pint --dirty` → pass
- `php artisan test --filter=CashflowAnalytics` → 24 passed
- `php artisan test --filter=Sync` → 166 passed
- `npm run build` → OK
- Post-fix audit: 0 real missing `__()` keys remaining
79075dbcdf